IMPROVED METHOD FOR DETECTING A QUENCH PHENOMENON, SYSTEM EXECUTING THE METHOD, AND AIRCRAFT.

Abstract

Method of controlling a superconducting electrical power line of an aircraft comprising at least two superconducting conductors arranged in the same cryostat, said method being carried out by an electronic circuit configured to determine a first electrical voltage representative of a first potential difference measured across the terminals of a first conductor among said at least two superconducting conductors; determine a second electrical voltage representative of a second potential difference measured across the terminals of the other conductor, said second conductor, among said at least two superconducting conductors; then, provide a first information representative of the presence of a potential difference greater than a predetermined threshold value between said first electrical voltage and said second electrical voltage.It is therefore advantageously possible to optimize the resources required for integrity control of an aircraft superconducting power line. Fig. 2.

Description

Title of the invention: IMPROVED METHOD FOR DETECTING A QUENCH PHENOMENON, SYSTEM EXECUTING THE METHOD, AND AIRCRAFT. technical field

[0001] The present invention relates to a superconducting power supply link for an electrical load, for example a motor, in an aircraft, particularly of the type usable for aircraft propulsion. The invention relates more particularly to the monitoring and control of a two-conductor superconducting power supply line in an aircraft. PREVIOUS STATE OF THE ART

[0002] The aeronautical industry is making profound changes in aircraft design, with the aim of significantly reducing carbon dioxide and nitrogen oxide emissions, due to ecological and sustainable development constraints.

[0003] The use of liquid hydrogen as an energy source for an aircraft is a promising approach. Hydrogen can be used in a fuel cell to generate electricity, or directly as fuel in a powertrain. Furthermore, work is specifically focused on optimizing electric or hybrid aircraft propulsion systems, and hydrogen in liquid form on board an aircraft can be used as a cooling source to enhance the performance of electrical equipment by lowering its resistivity and consequently reducing Joule effect losses. The use of superconducting components is also possible.Superconducting conductors can be used in superconducting technologies for DC (direct current) distribution components and for AC power distribution in architectures that include electric motors powered by controlled electronic power converters, such as inverters. In such motor power supply architectures, the superconducting links must be protected against an unexpected transition from the superconducting state to the conventional state (a transition commonly referred to as "quench" in the field of superconductivity). Therefore, it is important to be able to detect early warning signs of such a transition to prevent excessive Joule heating losses that could damage the power supply circuits and their surroundings.

[0004] Quench detection (i.e., transition detection) of a superconducting conductor is generally performed by monitoring the voltage across its terminals and by detecting the appearance of an increase in the voltage level across its terminals. While quench detection in continuous operation is fairly simple, as it only involves distinguishing between zero and non-zero impedance (i.e., resistance) of the conductor, the same is not true in transient operation. Indeed, a load such as a motor can cause a significant variation in current on the DC distribution network. In this case, the inductive part of the impedance is most often predominant compared to the resistive component, which prevents quench detection using standard methods. It is therefore necessary to implement a robust solution that eliminates the inductive effect on the voltage across the conductors during transient phases. Quench detection can then be based on a principle of detection in steady-state DC current (i.e., based on the variation of resistance).Since most of the superconducting elements used are magnets, it is generally sufficient to perform quench detection in only one of the conductors of the power supply link being monitored.

[0005] In a quench detection circuit according to the prior art, a coil forming a superconducting element monitored to detect a possible quench phenomenon is divided into two half-coils, and the two voltages measured across the terminals of the two half-coils must be identical. To verify this, a difference value between these two measured voltages is determined. This difference should be zero in the absence of a quench, even if there is a current transient, because the inductance is the same in both portions (half-coils) of the power line being measured. In the event of a problem with the power supply link, the impedance of one of the half-coils is no longer identical to the impedance of the other half-coil, and a voltage difference appears.

[0006] In a superconducting direct current distribution network (used to carry current from a source to a load), there is a conductor called the "positive conductor" and a conductor called the "negative conductor," which requires doubling the monitoring circuit described above. Furthermore, it is necessary to establish connections at a midpoint of each of the two conductors referred to as "positive" and "negative," respectively.

[0007] The situation can be improved. Description of the invention

[0008] An object of the present invention is to provide a controller for a superconducting power supply line of an electrical load, capable of rapidly and reliably detecting the occurrence of a quench-type phenomenon, so as to limit the current(s) delivered to the load when the superconducting power supply line enters the source and load is about to transition from a nominal superconducting state to a state in which its resistivity increases.

[0009] To this end, a method is proposed for controlling a superconducting direct current power supply line of an aircraft, said power supply line comprising at least two superconducting conductors arranged in the same cryostat, said method being executed by electronic circuitry configured to:

[0010] - determine a first electrical voltage representative of a first difference of potential measured across the terminals of a first conductor among said at least two superconducting conductors,

[0011] - determine a second electrical voltage representative of a second potential difference measured across the terminals of the other conductor, called the second conductor, among said at least two superconducting conductors, then,

[0012] - provide initial information representative of the presence of a difference in voltage greater than a predetermined threshold value between said first electrical voltage and said second electrical voltage.

[0013] It is thus advantageously possible to optimize the resources needed to control the integrity of an aircraft cryogenic power supply line.

[0014] According to one embodiment, the method further comprises providing a second piece of information according to which an anomaly is detected in relation to said first driver or conversely in relation to said second driver.

[0015] The invention also relates to a control device for a direct current power supply line of an aircraft, the power supply line comprising at least two superconducting conductors arranged in the same cryostat and the control device comprising electronic circuitry configured to: - determine a first electrical voltage representative of a first potential difference measured across the terminals of a first conductor among said at least two superconducting conductors, - determine a second electrical voltage representative of a second potential difference measured across the terminals of the other conductor, called the second conductor, among said at least two superconducting conductors, and for, - to provide initial information representative of the presence of a voltage difference greater than a predetermined threshold value between said first electrical voltage and said second electrical voltage.

[0016] According to one embodiment, the control device for a power supply line further comprises providing a second piece of information indicating that an anomaly is detected in relation to the first conductor or, conversely, in relationship with the second conductor of the power supply line.

[0017] The invention also relates to a cryogenic aircraft power supply system comprising a power supply line control device as previously described, configured to control a superconducting power supply line between an aircraft current source and an aircraft current-consuming device (load).

[0018] The invention also relates to an aircraft comprising an electrical power control device as described above or a cryogenic power system as described above.

[0019] The invention finally relates to a computer program product comprising program code instructions for executing the steps of a method for controlling a superconducting power line as previously described when said instructions are executed by a processor of a device for controlling a superconducting power line, as well as a storage medium comprising such a computer program product. Brief description of the drawings

[0020] The features of the invention mentioned above, as well as others, will become clearer upon reading the following description of an exemplary embodiment, said description being made in relation to the accompanying drawings:

[0021] [Fig-1] illustrates an aircraft comprising a line control device superconducting aircraft power supply configured to perform a control process for such a line;

[0022] [Fig.2] schematically illustrates implementation details of a control device for a superconducting aircraft power supply line;

[0023] [Fig.3] is a flowchart illustrating steps in a method for controlling a superconducting aircraft power supply line; and,

[0024] [Fig.4] illustrates an example of the architecture of a control device for a superconducting aircraft power supply line configured to perform the process already illustrated in [Fig.3].

[0025] DETAILED STATEMENT OF IMPROVEMENTS

[0026] Figure 1 schematically and symbolically represents an aircraft 1 comprising a control device 10 for a superconducting power supply line of the aircraft 1 (this device 10 is not detailed in Figure 1, but is illustrated in Figure 2). Advantageously, such a device installed in the aircraft 1 makes it possible to monitor the absence of quenching phenomena related to the superconducting power supply line, and to detect such a phenomenon as early as possible, as soon as it occurs.

[0027] Figure 2 schematically and symbolically illustrates the control device 10 of a power supply line connected to the ends of a superconducting power supply line EL of aircraft 1, configured to control this superconducting power supply line EL, and in particular to detect the occurrence of a quench phenomenon related to this power supply line. The superconducting power supply line EL includes, in particular, two superconducting conductors LCP and LCM cooled by a cryogenic fluid. By way of exception, the two superconducting conductors LCP and LCM may, for example, be arranged (immersed) in a cryogenic fluid within a cryostat CR enclosing the superconducting conductors LCP and LCM. The term cryostat here refers to a sealed enclosure designed to minimize heat exchange with the environment and containing a cryogenic fluid maintained at a cryogenic temperature.The superconducting conductor LCP is the first electrical superconducting conductor of the EL line, called the "positive conductor," and the superconducting conductor LCM is the second superconducting conductor of the EL line, called the "negative conductor." The superconducting power supply line EL is connected at one end between the terminals VG+ and VG- of a DC voltage source G. The other end of the power supply line EL is connected to a load LD, or in other words, to an energy-consuming device or system LD.

[0028] A first electronic circuit OA1 is configured to determine a first electrical voltage V+ representing a first potential difference measured across the terminals of the first superconducting conductor LCP of the two superconducting conductors LCP and LCM. The electrical voltage V+ is defined between the output of the electronic circuit OA1 and a reference ground (potential) GND1. Similarly, a second electronic circuit OA2 is configured to determine a second electrical voltage V- representing the potential difference measured across the terminals of the other conductor, LCM, referred to as the second conductor, of the two superconducting conductors LCP and LCM. The electrical voltage V- is defined between the output of the electronic circuit OA2 and a reference ground (potential) GND2.In addition, a third electronic circuit D1 is configured to provide at least one initial information Q, in the form of a signal, which represents the presence of a voltage difference greater than a predetermined threshold value between the first electrical voltage V+ and the second electrical voltage V-. The circuit DI is a voltage subtractor type circuit, for example based on operational amplifiers or implemented digitally. The control device 10 of a superconducting power supply line therefore comprises the three electronic circuits OA1, OA2, and DI.

[0029] According to one embodiment, the electronic circuitry DI further determines a signal S whose voltage is equal to V+ - V-. This second signal delivered by the electronic circuitry DI constitutes a second piece of information, indicating that an anomaly has been detected in relation to the first superconducting conductor LCP or in relation to the second superconducting conductor LCM. Indeed, if the sign of the difference between the voltages V+ - V- is positive, this implies that a problem has occurred in relation to the positive conductor LCP. Conversely, if the sign of the difference between the voltages V+ - V- is negative, this implies that a problem has occurred in relation to the negative conductor LCM.

[0030] In one embodiment, the electronic circuitry OA1 is an operational amplifier type circuit whose two inputs are respectively connected to the ends of the positive conductor LCP, and the electronic circuitry OA2 is an operational amplifier type circuit whose two inputs are respectively connected to the ends of the negative conductor LCM. In one embodiment, the electronic circuits OA1 and OA2 are respectively powered by independent power supply circuits that are galvanically isolated from each other (power supply and ground).

[0031] Figure 3 is a flowchart illustrating steps in a process for controlling the superconducting power supply line EL illustrated in [Fig.2].

[0032] The S0 step is an initialization step at the end of which all the aircraft 1's onboard systems useful for ground taxiing or flight, including the EL power supply line and the control device 10, are correctly configured and normally operational.

[0033] During step S1, the electronic circuitry OA1 determines the first electrical voltage V+ representing the potential difference measured across the terminals of the positive conductor of the superconducting power supply line EL. Simultaneously, during step S2, the electronic circuitry OA2 determines the second electrical voltage V- representing the potential difference measured across the terminals of the negative conductor of the superconducting power supply line EL. Once the voltages V+ and V- have been determined, the circuitry DI determines, during step S3, the voltage difference between the voltages V+ and V- and then provides, during step S4, the information Q representing the presence of a voltage difference greater than a predetermined threshold value between the voltage V+ and the voltage V-.

[0034] According to one embodiment, the predetermined threshold value is less than 100 mV, preferably on the order of a few millivolts. The threshold value depends in particular on several parameters, including the length of the supply line.

[0035] According to one embodiment, the method may include a step of filtering the first electrical voltage V+ and the second electrical voltage V-, or a step Filtering the voltage difference between the V+ and V- voltages is done to prevent spurious triggering and the transmission of erroneous S information. In one embodiment, the filtering is a low-pass filter designed to eliminate high-frequency spurious signals.

[0036] According to one embodiment, the DI circuitry further provides the information S representing the sign of the difference V+ - V-.

[0037] This information is provided for example to a device configured to supervise the control of the integrity of the installations and systems of aircraft 1 or of the integrity of a subset of these installations and systems.

[0038] Figure 4 is a schematic representation of an example of the internal architecture of the control device 10 for an aircraft superconducting power supply line. For illustrative purposes, Figure 4 shows an internal arrangement of the control device 10 as installed in the aircraft 1. It should be noted that Figure 4 could also schematically illustrate an example of the hardware architecture of a control or monitoring module comprising the control device 10 for an aircraft superconducting power supply line.

[0039] According to the hardware architecture example shown in [Fig.4], the control device 10 then comprises, connected by a communication bus 10-9: a processor or CPU (Central Processing Unit) 10-1; a RAM (Random Access Memory) 10-2; a ROM (Read Only Memory) 10-3; a storage unit such as a hard disk drive (or a storage media reader, such as an SD card reader (Secure Digital) 10-4); a communication interface module 10-5 enabling the control device 10 to communicate with remote devices, such as other onboard systems of the aircraft 1, for example one or more systems for monitoring the integrity of the systems of the aircraft 1.

[0040] The processor 10-1 of the control device 10 is capable of executing instructions loaded into RAM 10-2 from ROM 10-3, external memory (not shown), a storage medium (such as an SD card), or a communication network. When the control device 10 of a superconducting power line is powered on, the processor 10-1 is capable of reading instructions from RAM 10-2 and executing them. These instructions form a computer program causing the processor 10-1 to implement all or part of a method for controlling a superconducting power line described in relation to [Fig. 3] or described variants of this method.

[0041] All or part of the method described in relation to [Fig. 3] or its described variants can be implemented in software form by executing a set of instructions by a programmable machine, for example a DSP (Digital Signal Processor). English) or a microcontroller, or be implemented in hardware form by a dedicated machine or component, for example, an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit). In general, the control device 10 of an aircraft superconducting power line comprises electronic circuitry configured to implement the described process in relation to itself. Obviously, the control device 10 also includes all the elements usually present in a system comprising a control unit and its peripherals, such as a power supply circuit, a power supply monitoring circuit, one or more clock circuits, a reset circuit, input / output ports, interrupt inputs, and bus drivers; this list is not exhaustive.

Claims

Demands

1. A method for controlling a DC power supply line (PL) of an aircraft (1), said power supply line (PL) comprising at least two superconducting conductors (LCP, LCM) arranged in the same cryostat (CR), said method being carried out by electronic circuitry configured to: - determine (S1) a first electrical voltage V+ representing a first potential difference measured across the terminals of a first conductor (LCP) among said at least two superconducting conductors (LCP, LCM), - determine (S2) a second electrical voltage (V-) representing a second potential difference measured across the terminals of the other conductor (LCM), said second conductor (LCM), among said at least two superconducting conductors (LCP, LCM), then,- provide (S4) initial information (Q) representative of the presence of a voltage difference exceeding a predetermined threshold value between said first electrical voltage (V+) and said second electrical voltage (V-).

2. Method of controlling an electrical supply line according to claim 1, further comprising providing a second piece of information (S) according to which an anomaly is detected in relation to said first conductor (LCP) or in relation to said second conductor (LCM).

3. Control device (10) for a DC power supply line (PL) of an aircraft (1), said power supply line (PL) comprising at least two superconducting conductors (LCP, LCM) arranged in the same cryostat (CR), said control device (10) comprising electronic circuitry configured to: - determine (S1) a first electrical voltage (V+) representing a first potential difference measured across the terminals of a first conductor (LCP) among said at least two superconducting conductors (LCP, LCM), - determine (S2) a second electrical voltage (V-) representing a second potential difference measured across the terminals of the other conductor (LCM), called second conductor (LCM), among the said at least two superconducting conductors (LCP, LCM), then, - provide (S4) a first information (Q) representative of the presence of a voltage difference greater than a predetermined threshold value between said first electrical voltage and said second electrical voltage.

4. Control device for an electrical supply line (EL) according to claim 3, further comprising providing a second piece of information (S) that an anomaly is detected in relation to said first conductor (LCP) or in relation to said second conductor (LCM).

5. Cryogenic power supply system of an aircraft (1) comprising a control device (10) of a power supply line (EL) according to any one of claims 3 and 4 configured to control a cryogenic power supply line between a current source (G) of said aircraft (1) and a current-consuming device (LD) of said aircraft (1).

6. Aircraft (1) comprising a power supply line control device (10) according to any one of claims 3 and 4 or a cryogenic power supply system according to claim 5.

7. Product computer program comprising program code instructions to execute the steps (S1, S2, S4) of a process according to any one of claims 1 to 2 when said instructions are executed by a processor of a control device (10) of a power supply line.

8. Storage medium comprising a computer program product according to claim 7.

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