Power distribution method and system configured to power electric motor of aircraft from at least one power source

Abstract

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

Description

Technical Field

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

[0002] Climate change is a major concern for many members of legislative and regulatory bodies around the world. Various limits on carbon emissions have been, are being or will be adopted by various countries. In particular, the desired standards apply both to new aircraft and those already in circulation, requiring the implementation of technical solutions to bring them into line with existing regulations. For several years, civil aviation has been committed to helping combat climate change.

[0003] Technological research has led to significant improvements in the environmental performance of aircraft. Applicants have taken into account influencing factors at all stages of design and development to obtain aviation components and products that consume less energy, are more environmentally friendly, and have a moderate environmental impact when integrated and used in civil aviation, in order to improve the energy efficiency of aircraft.

[0004] Therefore, the Applicant continuously strives to reduce the environmental footprint of its operations by adopting approaches that use benign development and manufacturing methods to reduce its negative impact on the climate and reduce greenhouse gas emissions to the minimum possible amount.

[0005] This ongoing research and development work covers the next generation of aircraft electric motors and the use of electrical technology for propulsion.

[0006] In a known manner, reference Figure 1 , the aircraft may comprise several electric motors M11 to M14 allowing its propulsion, these motors being powered by two batteries B11, B12 via a power distribution system 100. In this example, the power distribution system 100 comprises a first electrical switch C11 connected on the one hand to the first battery B11 and on the other hand to the two propulsion motors M11, M12. The power distribution system 100 also comprises a second electrical switch C12 connected on the one hand to the second battery B12 and on the other hand to the other two propulsion motors M13, M14.

[0007] In order to ensure that the motors M11 to M14 are powered in the event of an isolation fault, it is proposed to use a power distribution system 100 with a so-called "isolated" architecture, i.e. allowing the batteries B11, B12 to take over each other in the event of a fault. The first switch C11 is connected to the second battery B12 via a first reconstruction line R1. Similarly, the second switch C12 is connected to the first battery B11 via a second reconstruction line R2. The electrical reconstruction lines R1, R2 are preferably unidirectional and only allow current to flow in one direction to avoid simultaneous faults. Each reconstruction line R1, R2 includes one or more reconstruction switches IR1, IR2 to power the switches C11, C12 when the batteries B11, B12 are unavailable.

[0008] A short circuit may occur in the power distribution system 100. When a short circuit occurs, the power supply from the power sources B11, B12 is immediately cut off to protect the power distribution system 100. For the power distribution system 100 including the power sources B11, B12 having high voltage, it is impossible to use conventional safety equipment. Figure 2 As shown, the short-circuit current Icc may reach tens of thousands of volts in a very short time. The higher the current flowing through the wire, the more difficult it is to disconnect the wire.

[0009] To eliminate this shortcoming, refer to Figure 3 , it has been proposed to provide different protection components in the power distribution system 100. For the sake of clarity, Figure 3 Only a portion of the power distribution system 100 related to the first battery B11 is shown.

[0010] In particular, the power switch 102 is mounted on a power line LS connecting the first battery B11 to the first switch C11. Similarly, load switches 141, 142 are mounted on each electrical load line LC1, LC2 connecting the first switch C1 to its associated propulsion motor M11, M12. In a known manner, the power distribution system 100 also comprises a monitoring device 105 comprising measuring sensors and a computer in order to measure the electrical parameters of the power distribution system 100 and to infer the control of the switches 102, 141, 142 in the event of a short circuit, as described below.

[0011] In the nominal mode of operation, the switches 102, 141, 142 are closed. When a short circuit is detected, the monitoring device 105 immediately controls the opening of the power switch 102 to limit the increase of the short circuit current. This avoids having to close a very high short circuit current that could cause damage. Therefore, the first battery B11 is isolated.

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

[0013] Therefore, the conversion between the nominal mode and the degraded mode of the distribution system 100 is achieved through the following steps: the first step is to isolate the first battery B11 to stop the power supply to the distribution system 100; the second step is to isolate the faulty power line; and the third step is to re-power the distribution system 100 by the first battery B11.

[0014] In practice, the first step of disconnecting the first battery B11 is disadvantageous because the electric motors M11, M12 are no longer powered. As a result, the interruption of the power supply to the electric motors M11, M12 is very short, less than 1 second, which may generate a jolt in the propulsion of the aircraft, which is a disadvantage. The first switch C11 generally comprises a capacitor, which needs to be charged in order to allow the first switch C11 to perform its function. With the disconnection of the first battery B11, the capacitance of the first switch C11 is discharged.

[0015] Furthermore, the power switch 102 is typically in the form of a solid-state power controller (SSPC) switch because this allows the power switch 102 to open very quickly when a short circuit is detected. Such a power switch 102 is expensive and complex to integrate into the power distribution system 100, which presents another disadvantage.

[0016] Prior art patent application WO2021210124 introduces a power supply system with a current limiting device. Summary of the invention

[0017] The present invention relates to a power distribution system, which is configured to supply power to at least a first electric motor and a second electric motor from at least one power source, the electric motors being aircraft propulsion motors, the power distribution system comprising:

[0018] at least one switch configured to be connected to the power supply via a power line on the one hand and to each motor via an electrical load line on the other hand,

[0019] At least one disconnecting device mounted on the power line and configured to disconnect the power line after a predetermined time delay in the presence of a short circuit current.

[0020] At least one current limiter mounted on the power line between the disconnect device and the switch and configured to allow a limited current to flow through the switch for a limited period of time greater than a predetermined delay in the presence of a short circuit current.

[0021] Thanks to the invention, the power distribution system is always powered within the restricted period, so the short circuit can be isolated without stopping the switches and the motors. Thus, the short circuit can be isolated without causing a jolt in the propulsion of the aircraft, which is advantageous. The presence of the disconnection device allows the power distribution system to be protected before the restricted period ends.

[0022] Preferably, the current limiter is configured to dissipate at least 300 kW of power, preferably at least 400 kW of power within the limiting period. Such a current limiter allows providing sufficient time to break the short circuit. Preferably, the limiting period is greater than 100 ms.

[0023] According to a preferred aspect, the predetermined delay is between 100 ms and 300 ms. Such a delay allows providing sufficient time to isolate the short circuit while allowing the short circuit to be cut off at a compatible short circuit current value.

[0024] Preferably, the power distribution system comprises at least one load switch mounted on the electrical load line. Preferably, each electrical load line is provided with a load switch.

[0025] Preferably, the load switch is configured to automatically enter the disconnected state when a load current greater than a predetermined current threshold flows in the electrical load line for a predetermined flow time. In this way, the load switch implements a fuse function to cut off a short circuit.

[0026] Preferably, the predetermined flow time is less than the predetermined delay. In this way, the short circuit is isolated before the power supply is cut off, thereby avoiding such a circuit break.

[0027] Preferably, the current threshold is smaller than the limited current so that the load switch can achieve its function while limiting the current.

[0028] Preferably, the load switch is a thermal switch.

[0029] The invention also relates to an electrical architecture comprising at least one power source, at least one first electric motor and a second electric motor, the electric motor being an aircraft propulsion motor, the architecture comprising a power distribution system as proposed above, in order to supply power to the electric motor from the power source.

[0030] The invention also relates to an aircraft comprising an architecture as proposed above.

[0031] The invention also relates to a method of distributing electricity carried out in an electricity distribution system for supplying electricity from at least one power source to at least a first electric motor and a second electric motor, the electric motors being aircraft propulsion motors, the electricity distribution system comprising at least one switch connected to the power source via a power line on the one hand and to each electric motor via an electric load line on the other hand, the method comprising the steps present in the following aspects:

[0032] If a short circuit current is present, the current is limited in the switch to a limited current value for a limited period of time, and

[0033] If a short circuit current is present, the power line is disconnected after a predetermined delay, which is less than the limit period.

[0034] Preferably, the distribution method comprises the step of automatically switching to the disconnected state when a load current greater than a predetermined current threshold flows in the electrical load line for a predetermined flow time less than a predetermined delay.

[0035] Preferably, the distribution method comprises the step of disabling the current limitation in the switch following the disappearance of the short-circuit current. This allows a time delay for stopping, rather than disconnecting the power line. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The invention will be better understood on reading the following description given by way of example and with reference to the following drawings given by way of non-limiting example, in which the same references are used for similar objects.

[0037] Figure 1 It is a schematic diagram of a power distribution system in the prior art.

[0038] Figure 2 is a schematic diagram of the evolution of short-circuit current in a distribution system.

[0039] Figure 3 yes Figure 1 A close-up schematic of the portion of the power distribution system shown in .

[0040] Figure 4 is a schematic diagram of a power distribution system according to an embodiment of the present invention.

[0041] Figure 5 , Figure 6 , Figure 7 and Figure 8 It is for local short circuit on the load line. Figure 4 Schematic diagram of the current flowing in the power distribution system shown.

[0042] Fig. 9 and Fig.10 It is for local short circuit on the power line. Figure 4 Schematic diagram of the current flowing in the power distribution system shown.

[0043] It should be noted that these drawings illustrate the invention in detail in order to implement the invention and, if necessary, these drawings can of course be used to better define the invention. DETAILED DESCRIPTION

[0044] An aircraft will now be proposed which comprises an electrical architecture to ensure the propulsion of the aircraft.

[0045] refer to Figure 4 , shows an electrical structure comprising a first electric motor M1 and a second electric motor M2 for propelling an aircraft. However, the present invention is applicable to more than two electric motors M1, M2, in particular to four electric motors.

[0046] To power the electric motors M1 , M2 , the electrical architecture comprises one or more power sources B1 , in particular batteries. In the present example, only a single power source B1 is shown for the sake of clarity.

[0047] According to the invention, the electrical architecture comprises a power distribution system 1 configured to transmit power between one or more power sources B1 and electric motors M1, M2. This energy transfer is preferably bidirectional to allow the power source B1 to be recharged (generator operation) via the electric motors M1, M2.

[0048] In this example, reference Figure 4 , the power distribution system 1 comprises a first electrical switch C1 which is connected on the one hand to the power supply B1 and on the other hand to the two motors M1 , M2. This allows a power supply channel to be formed. For the sake of clarity, a single power supply channel is shown, but it goes without saying that there may be more power supply channels.

[0049] Preferably, the power distribution system 1 comprises a "disconnected" power supply channel, ie allowing the power sources to take over each other in case of a failure. Preferably, the power distribution system 1 comprises a reconstruction line as described above.

[0050] According to the present invention, reference Figure 4 , the power distribution system 1 comprises a switch C1 connected on the one hand to a power supply B1 via a power supply line LS and on the other hand to each motor M1 , M2 via an electrical load line LC1 , LC2. In the present example, the switch C1 is in the form of a power supply bus, preferably a high voltage bus.

[0051] According to the invention, the power distribution system 1 comprises a disconnection device 2 mounted on the power line LS, the disconnection device 2 being configured to disconnect the power line LS after a predetermined delay D2 in the presence of a short-circuit current Icc.

[0052] The circuit breaker device 2 is preferably in the form of a contactor, which is preferably an electromagnetic contactor combined with a current sensor and a timer. The predetermined delay D2 depends on the current that may be cut off. In this example, the predetermined delay D2 is between 100ms and 300ms to achieve circuit interruption of up to 1500A.

[0053] If the short circuit is not handled within the predetermined delay time D2, the circuit breaker device 2 allows the power supply to the power line LS to be cut off. This prevents damage to the power distribution system 1 and thus fire.

[0054] like Figure 4 As shown, the power distribution system 1 includes a current limiter 3, which is installed on the power line LS between the circuit breaker device 2 and the switch C1. The current limiter 3 is configured such that if there is a short-circuit current Icc, the current limiter 3 allows a limited current Ilim to flow through the switch C1 within a limited period D3. Such a current limiter 3 advantageously allows the switch C1 to be powered with a limited current Ilim allowed by the switch C1 in the event of a short circuit.

[0055] In this example, the value of the limited current Ilim is between 400 A and 700 A, preferably between 500 A and 600 A. The short-circuit current Icc may be around 4000 A. In particular, this value is determined as a function of the properties of the load switches 41 , 42 , as will be described later.

[0056] The current limiter 3 is configured to consume electrical energy, in particular in the form of heat, during the limited period D3. Preferably, the current limiter 3 is configured to consume a power greater than 300 kW, greater than 400 kW during the limited period D3.

[0057] The limiting period D3 is preferably greater than 100 ms to allow the power distribution system 1 to switch to a degraded mode, as described below. Preferably, the limiting period D3 is between 500 ms and 1000 ms.

[0058] Preferably, the current limiter 3 is in the form of a semiconductor current limiter, a thermistor, a resistive superconductor, a parallel inductive superconductor, or the like.

[0059] According to the present invention, the limit period D3 is greater than the predetermined delay time D2 (D3>D2) to allow the disconnection device 2 to cut off the power supply to the power source B1 if the degraded mode is not feasible.

[0060] Activating the circuit-breaking device 2 before the end of the limit period D3 advantageously protects the switch C1 and the motors M1 , M2 from high-value short-circuit currents Icc.

[0061] Still reference Figure 4 , the first load switch 41 and the second load switch 42 are respectively installed on the first electrical load line LC1 and the second electrical load line LC2.

[0062] However, the invention is also applicable to load switches 41, 42 mounted on a single electrical load line LC1, LC2.

[0063] In this example, each load switch 41, 42 is configured to automatically switch to the off state when a load current Ic1, Ic2 greater than a predetermined current threshold Iseuil flows in the electrical load lines LC1, LC2 for a predetermined flow time D4.

[0064] In this way, when the flowing current (load currents Ic1, Ic2) is too high, i.e., greater than the predetermined current threshold Iseuil, the load switches 41, 42 implement the fusing function of disconnecting the electrical load lines LC1, LC2.

[0065] Preferably, the predetermined flow time D4 is less than the predetermined delay D2. In other words, before the power supply is stopped by the circuit breaker 2 at the end of the predetermined delay D2, each load switch 41, 42 has enough time to implement its fusing function.

[0066] The predetermined flow time D4 must be long enough to avoid unwanted disconnections and must be short enough to avoid using the current limiter 3 with a long limiting period D3 and the circuit breaker 2 that must disconnect high currents, which would increase the cost and overall size of the power distribution system 1. This gives the following relationship: D4 < D2 < D3. Preferably, the predetermined flow time D4 is between 10 ms and 50 ms.

[0067] Advantageously, the current threshold Iseuil is lower than the limited current Ilim limited by the current limiter 3 so as to allow the load switches 41, 42 to implement their fusing function when the current limiter 3 is activated in the presence of a short - circuit current Icc.

[0068] Preferably, each load switch 41, 42 is a thermal switch or a high - temperature fuse.

[0069] Example 1 of the embodiment: A short - circuit (short - circuited circuit) CC on the first electrical load line LC1 ( Figures 5 to 8 ).

[0070] Now a first example of an embodiment of a power distribution method for the power distribution system 1 as Figure 4 shown is presented.

[0071] In this example, referring to Figure 5 , there is a short - circuit CC on the first electrical load line LC1 between the switch C1 and the first motor M1. When the short - circuit CC occurs, a short - circuit current Icc flows between the power supply B1 and the short - circuit CC. No current flows on the second electrical load line LC2, and the current is conducted to the short - circuit CC.

[0072] Referring to Figure 6The method comprises the steps of limiting the current E1 to a limited current value Ilim in the switch 3 in the presence of a short-circuit current Icc within a limited period D3. The current limiter 3 reduces the short-circuit current Icc. Figure 6 As shown, the load current Ici corresponds to the limited current Ilim in the first electrical load line LC1.

[0073] refer to Figure 7 , the method comprises the steps present in the following aspects: when the load current Ic1 is greater than the predetermined current threshold Iseuil within the predetermined flow time D4, automatically disconnecting E2 the first electrical load line LC1. Since the value of the limited current Ilim is greater than the predetermined current threshold Iseuil, the load switch 41 disconnects the first electrical load line LC1 at the end of the predetermined flow time D4. In this way, the first load switch 41 realizes its function as a fuse and disconnects the first motor M1, which can no longer be powered.

[0074] refer to Figure 8 , with the short circuit CC disconnected, there is no longer any short circuit current Icc and the method comprises a step E3 of inhibiting the limitation. The current limiter 3 substantially supplies the second electric motor M2. The power distribution system 3 is therefore in a degraded mode. Contrary to the prior art, the power supply of the switch C1 is maintained by the current limiter 3, which prevents its capacitance from being discharged. The second electric motor M2 continues to contribute to the propulsion without the pilot or the passengers noticing any jolt.

[0075] This example of embodiment is particularly advantageous in the case of a latent short circuit which disappears before the end of the predetermined flow time D4. Thanks to the current limiter 3, the electric motors M1, M2 continue to contribute to propulsion without causing any jolts to the pilot or passengers.

[0076] Example 2 of Implementation: Short Circuit (Short Circuit) CC on Power Line LS ( Figures 9 and 10 ).

[0077] It is now proposed to be used for Figure 4 A second example of an implementation of a power distribution method of a power distribution system 1 is shown.

[0078] In this example, reference Fig. 9 , there is a short circuit CC on the first power line LS between the current limiter LS and the switch C1. When the short circuit CC occurs, the short circuit current Icc flows between the power source B1 and the short circuit CC. No current flows on the electrical load lines LC1, LC2.

[0079] Still reference Fig. 9The method comprises the steps in the following aspects: if there is a short-circuit current Icc, limiting the current E1 to a limited current value Ilim in the switch 3 within a limited period D3. The current limiter 3 reduces the short-circuit current Icc.

[0080] This state means that no current flows on the electrical load lines LC1 , LC2. The load switches 41 , 42 remain closed.

[0081] refer to Fig.10 , the method comprises the step of disconnecting E4 the power supply line LS after a predetermined delay D2. Since the short-circuit current Icc is still present, the disconnection device 2 disconnects the power supply line LS in order to protect the switch C1 before the end of the limit period D3. The predetermined delay D2 allows the power supply to be cut off until the short-circuit current Icc is too high.

[0082] Since the power distribution system 1 of the invention can be switched to a degraded mode, it does not cause violent jolts during aircraft propulsion. Furthermore, a judicious setting of the current values, thresholds and various time periods D2, D3, D4 allows for a very responsive trip in the event of a short circuit. The safety and availability of the propulsion system are further enhanced.

Claims

1. A power distribution system (1) configured to supply power from at least one power source (B1) to at least a first electric motor (M1) and a second electric motor (M2), wherein the electric motors (M1, M2) are aircraft propulsion motors, the power distribution system (1) comprising: at least one switch (C1) configured to be connected on the one hand to said power source (B1) via a power line (LS) and on the other hand to each electric motor (M1, M2) via an electric load line (LC1, LC2), at least one disconnecting device (2) mounted on said power line (LS) and configured to disconnect said power line (LS) after a predetermined delay (D2) in the presence of a short-circuit current (Icc), at least one current limiter (3) mounted on the power line (LS) between the disconnecting device (2) and the switch (C1) and configured to allow, in the presence of the short-circuit current (Icc), a limited current (Ilim) to flow through the switch (3) for a limited period (D3) greater than the predetermined delay (D2), the value of the limited current (Ilim) being between 400 A and 700 A, the limited period (D3) being greater than 100 ms.

2. The power distribution system (1) according to claim 1, wherein the current limiter (3) is configured to consume at least 300 kW of power, preferably at least 400 kW of power, within the limited time period (D3).

3. Power distribution system (1) according to one of claims 1 to 2, wherein the predetermined delay (D2) is between 100 ms and 300 ms.

4. Electricity distribution system (1) according to one of claims 1 to 3, comprising at least one load switch (41, 42) mounted on an electric load line (LC1, LC2).

5. The power distribution system (1) according to claim 4, wherein the load switch (41, 42) is configured to automatically enter an open state when a load current greater than a predetermined current threshold (Iseuil) flows in the electrical load line (LC1, LC2) for a predetermined flow time (D4).

6. The power distribution system (1) according to claim 5, wherein the predetermined flow time (D4) is smaller than the predetermined delay time (D2).

7. The power distribution system (1) according to one of claims 4 to 6, wherein the current threshold (Iseuil) is smaller than the limited current (Ilim).

8. An electrical architecture comprising at least one power source (B1), at least one first electric motor (M1) and a second electric motor (M2), the electric motors (M1, M2) being aircraft propulsion motors, the architecture comprising a power distribution system (1) according to one of claims 1 to 7 so as to supply power to the electric motors (M1, M2) from the power source (B1).

9. A method for distributing electricity in a power distribution system (1), the power distribution system (1) supplying power from at least one power source (B1) to at least a first electric motor (M1) and a second electric motor (M2), the electric motors (M1, M2) being aircraft propulsion motors, the power distribution system (1) comprising at least one switch (C1), the at least one switch (C1) being connected on the one hand to the power source (B1) via a power line (LS) and on the other hand to each electric motor (M1, M2) via an electric load line (LC1, LC2), the method comprising the steps present in the following aspects: if a short circuit current (Icc) is present, limiting the current (E1) in the switch (3) to a limited current value (Ilim) between 400A and 700A within a limited period (D3), the limited period (D3) being greater than 100ms, and If a short-circuit current (Icc) is present, disconnecting (E4) said power supply line (LS) after a predetermined delay (D2), said predetermined delay (D2) being less than said limit period (D3).

10. The power distribution method according to claim 9 comprises the steps of automatically disconnecting (E2) the electric load lines (LC1, LC2) when a load current greater than a predetermined current threshold (Iseuil) flows in the electric load lines (LC1, LC2) for a predetermined flow time (D4) less than the predetermined delay (D2).

11. Power distribution method according to claim 10, comprising the step of disabling (E3) the current limitation in said switch (3) as said short-circuit current (Icc) disappears.

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