IMPROVED SUPERCONDUCTIVE POWER LINE, METHOD FOR CONTROLLING A SUPERCONDUCTIVE POWER LINE AND AIRCRAFT COMPRISING SUCH A LINE.

Abstract

The invention relates to a method for controlling a superconducting power line (100) implemented in a control circuit (10). The method comprises obtaining (S1) information representing a first electric current in said superconducting power line, and then, if (S2) said information representing a first electric current is greater than or equal to a first predetermined threshold value, generating a current (S3), called a second current, in a superconducting coil (108) arranged near said power line (100). The value of said second current is determined from said information representing said first current. The invention also relates to a control circuit (10) configured for implementing the method.Thus, it is possible to reversibly operate current limiting functions by initiating a quench phenomenon in the said superconducting power supply line. Fig. 1.

Description

Title of the invention: IMPROVED SUPERCONDUCTIVE POWER SUPPLY LINE, METHOD FOR CONTROLLING A LINE SUPERCONDUCTIVE POWER SUPPLY AND AIRCRAFT INCLUDING SUCH A LINE. technical field

[0001] The present invention relates to a superconducting power supply circuit equipped with a current controller. The invention relates more particularly to the monitoring and control of the integrity of a superconducting aircraft power link, and to an aircraft comprising such a power link. 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 avenue for achieving this is hydrogen. It can be used in a fuel cell to generate electricity or directly as fuel in a powertrain. Furthermore, research is specifically focused on optimizing electric or hybrid aircraft propulsion systems, and liquid hydrogen on board an aircraft can be used to enhance the performance of electrical equipment by lowering its resistivity and consequently reducing Joule heating losses. Superconducting components can also be used. Superconducting conductors can be employed for power distribution in architectures comprising various electrical components powered by superconducting power distribution networks.In such power supply architectures, the superconducting link between a source and a load must be protected against an unexpected transition from the superconducting state to the conventional state (a transition usually called quench in the field of superconductivity). It is therefore important to be able to detect signs of such a transition in order to avoid excessive Joule heating losses that could damage the power supply circuits and their immediate surroundings.

[0004] Furthermore, faults which occur in such power distribution networks must be dealt with quickly and reliably to avoid any damage to the systems.

[0005] Fault current limiters (also known as fault current limiters) have manufacturing-calibrated current-limiting characteristics that are not easily adaptable to specific operating conditions. Furthermore, while superconducting fuses can interrupt current in branches of a superconducting distribution network, their activation is irreversible and requires replacement, thus necessitating maintenance. Finally, devices such as solid-state circuit breakers can also be used to interrupt current in branches of a superconducting power distribution network, but they pose a risk to system integrity in the event of a failure. Moreover, solid-state circuit breakers exhibit significant Joule losses during nominal operation.

[0006] Furthermore, the impedance of such power distribution networks is lower than the impedance standards of electrical networks conventionally integrated into an aircraft. In conventional networks, the distribution system, as well as the cables, introduce impedances that act as dampers for current variations, thus stabilizing the network. With superconducting technologies, achieving zero direct current resistivity, particularly in the cables, presents a major drawback regarding network stability. In the case of a low-impedance network, the network stability margins are reduced or even eliminated, jeopardizing the compatibility of the source and the loads connected to this common network and potentially leading to an unstable network. Under these conditions, the supplied systems cannot function and may be damaged.

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

[0008] An object of the present invention is to propose a method for obtaining reversible current limiting functions in a superconducting power supply line reproducing the functions of a traditional fault current limiter.

[0009] To this end, a method for controlling a superconducting power supply line is proposed, the method being carried out in a control circuit of said power supply line and comprising the steps:

[0010] - i) obtain information representative of a first electric current in said superconducting power line,

[0011] - ii) compare said information representative of a first electric current in said superconducting power supply line with a first predetermined threshold value, and,

[0012] - iii) if said information representing a first electric current is greater than or equal to the first predetermined threshold value, generate a current, called second current, in a superconducting coil arranged near said superconducting power line and configured to emit a magnetic field, said superconducting power line being configured to receive said magnetic field, the value of said second current being determined from said information representative of said first current.

[0013] It is thus advantageously possible to regulate the current in a superconducting power supply line dynamically by adjusting a current limit according to the electrical distribution requirements. The invention thus provides protection for the power supply line in the event of a detected fault, as well as improving the stability of said power supply line.

[0014] According to one embodiment, the method further includes a step of melting a calibrated break zone of the power supply line when the first electric current has an intensity greater than a second predetermined threshold value for a predetermined time.

[0015] Another object of the invention is a control circuit for a superconducting power supply line, the control circuit comprising electronic circuitry configured to:

[0016] - i) obtain information representative of a first electric current in said superconducting power line,

[0017] - ii) compare said information representative of a first electric current in said superconducting power supply line with a first predetermined threshold value, and for,

[0018] - iii) if said information representing a first electric current is greater than or equal to the predetermined threshold value, generate a second current in a superconducting coil arranged near said superconducting power line and configured to emit a magnetic field, said superconducting power line being configured to receive said magnetic field, the value of said second current being determined from said representative information of said first current.

[0019] Advantageously, the control circuit of a superconducting power supply line as described above further comprises a calibrated break zone of the superconducting power supply line configured to melt when the The first electric current is greater than a second predetermined threshold value for a predetermined time.

[0020] Another object of the invention is a control system for a superconducting power supply line comprising a control circuit as previously described and a superconducting coil powered by the control circuit and arranged near the power supply line and configured to emit a magnetic field, said superconducting power supply line being configured to receive said magnetic field.

[0021] The invention also relates to an aircraft comprising at least one control circuit for a superconducting power line as previously described or a control system as mentioned above.

[0022] The invention further relates to a computer program product comprising program code instructions for executing the steps of the process as described, when said program is executed by a processor of a control circuit of a superconducting power supply line and a storage medium comprising such a computer program product. Brief description of the drawings

[0023] 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:

[0024] [Fig-1] illustrates a superconducting power supply line equipped with a current control circuit according to one embodiment;

[0025] [Fig.2] illustrates a variant of the superconducting power supply line with a current control circuit already shown in [Fig.1];

[0026] [Fig.3] is a flowchart illustrating a method for controlling a superconducting power supply line, carried out in a control circuit, according to one embodiment;

[0027] [Fig.4] schematically illustrates an example of the internal architecture of a controller device operating in a control circuit of a superconducting power supply line, according to one embodiment; and,

[0028] [Fig.5] illustrates an aircraft comprising a controlled superconducting power supply line according to one embodiment.

[0029] DETAILED STATEMENT OF IMPROVEMENTS

[0030] Figure 1 is a schematic representation of a control circuit 10 of a superconducting power supply line 100. The superconducting power supply line 100 is made of at least one superconducting material and is subjected to conditions satisfactory for operation in the superconducting state. of the superconducting power supply line 100. The conditions for superconducting operation of the superconducting power supply line 100 include, in particular, temperature conditions, magnetic environment conditions, and current density conditions. The superconducting power supply line 100 has two ends 100a and 100b, respectively connected to an electrical power source and to a receiving device, circuit, or system that consumes electrical power (not shown in the figure). In one embodiment, the superconducting power supply line 100 is in the form of a ribbon or a cable.Advantageously, a current sensor 102 is arranged on the superconducting power supply line 100 and is configured to deliver to a controller device 104 information representative of the intensity of the current flowing in the superconducting power supply line 100. The current sensor 102 delivers the information representative of the current flowing in the superconducting power supply line 100 to the controller device 104 via a link 106, also referred to here as the connection link 106.In one embodiment, the current sensor 102 is an electronic device comprising one or more conductive windings arranged around the superconducting power supply line 100, the terminals of which are respectively connected to current measurement inputs of the current sensor 102. The current sensor then sends an analog or digital quantity, the amplitude or value of which is proportional to the measured electric current intensity, to the controller device 104 via the connection link 106. In another embodiment, the winding(s) are directly connected to inputs of the controller device 104, and the terminals of the winding(s) then jointly constitute the connection link 106.According to one embodiment, the amplitude or value addressed by the current sensor 102 is defined during a laboratory calibration phase and is extracted from a table of values ​​stored in a non-volatile memory of the current sensor 102.The control circuit 10 of the superconducting power supply line 100 further includes a superconducting winding 108, also referred to herein as a "coil" 108, physically arranged near the superconducting power supply line 100, such that when an electric current flows through the coil 108, an induced magnetic field is applied to the superconducting power supply line 100. This induced magnetic field is such as to modify the superconducting conditions of the superconducting power supply line 100, and in particular to initiate a quenching phenomenon capable of increasing the resistivity of the superconducting power supply line 100 and thus increasing its electrical resistance. Alternatively, the magnetic field lines generated by the coil 108 can be guided. within a magnetic circuit made using an assembly of ferromagnetic materials. The coil 108 comprises two terminal conductors 108a and 108b, also referred to here as poles or terminals, connected to outputs of a current generator internal to the controller device 104. The controller device 104 is configured to deliver a current generated in the coil 108, the intensity of which is a function of information representative of the current flowing in the superconducting power supply line 100. Alternatively, the controller device 104 may include a controller whose function is to acquire the current measurement and deliver a current supply command to the coil 108, as well as a power stage, connected to said controller, whose function is to generate the current in the coil 108 in response to the supply command received from the controller.In other words, if ISC2 (called here second current) is the current intensity in coil 108 and ISCi (called here first current) is the current intensity in superconducting power supply line 100, then ISC2 = / (Isci) and / is a function defined during laboratory calibration tests so as to be able to implement, by the control circuit 10, a current limiting function in superconducting power supply line 100.Indeed, the arrangement of the control circuit 10 is such that if a fault occurs in an electrical power distribution network connected to the superconducting power supply line 100, an increase in the intensity of the first current ISci is detected by the current sensor 102 and transmitted to the controller 104 which determines the second current ISC2 according to the value of the first current ISC1, or more precisely according to information representative of the intensity of the first current ISCi, so as to generate a magnetic field B induced in the coil 108 and consequently induced in the superconducting power supply line 100.The operating characteristics of the superconducting power supply line 100 are modified by the presence of the magnetic field B to which the power supply line is subjected, leading to a so-called limit state. This limit state corresponds to the controlled onset of a quench phenomenon, which causes an increase in the resistance of the superconducting power supply line 100 and therefore the appearance of a voltage between its ends 100a and 100b, and consequently, a decrease in the current flowing through it. Thus, the described arrangement of the control circuit 10 of the superconducting power supply line 100 cleverly and advantageously allows the resistance of the power supply line, and therefore the current in the superconducting power supply line 100, to be controlled in the event of a fault in an electrical distribution network connected to the power supply line 100.The presence of a fault is determined when the value of the intensity of the first one. current II which flows in the superconducting power supply line 100 becomes greater than or equal to a first predetermined threshold value.

[0031] Advantageously, the first predetermined threshold value can vary according to predetermined operating modes of the superconducting power supply line 100. For example, the first threshold value can be equal to a value corresponding to a moderate power distribution regime, or to another value corresponding to a nominal power distribution regime, or even to a value corresponding to a full power (maximum power) distribution regime.

[0032] Figure 2 illustrates a variant of the control circuit 100 of the superconducting power supply line 100, in which the superconducting power supply line 100 further has a melting initiation zone 100f calibrated to melt when the current intensity in the superconducting power supply line 100 is greater than or equal to a second threshold value for a predetermined time. Advantageously, such a configuration allows the current flow in the superconducting power supply line 100 to be interrupted (by breaking and opening it) in the event of a malfunction of the control circuit 10, for example, due to a malfunction of the controller device 104.This consequently makes it possible to prevent or limit the effects induced by the installation of a quench phenomenon and excessive energy dissipation by Joule effect in the power distribution systems described or in neighboring systems.

[0033] The [Fig.3] is a flowchart type diagram which illustrates steps of a control process carried out by the control circuit 10 of the superconducting power supply line 100.

[0034] A step S0 includes initialization and configuration operations of the set of systems present aimed at obtaining a nominal state defined as a normally operational configuration for use of the superconducting power supply line 100, of the set of systems that this power supply line supplies and of the control circuit 10.

[0035] A step SI includes a measurement of the intensity of the first ISci current flowing in the superconducting power supply line 100 by the current sensor 102 and the provision of information representative of this intensity of the ISci current to the control device 104 via the connection link 106.

[0036] During a step S2, the control device 104 reads the information representing the intensity of the current ISci flowing in the superconducting power supply line 100 and determines whether the current ISci is greater than or equal to to a first predetermined threshold value. If the current ISCi is not greater than or equal to the first predetermined threshold value, then the process returns to step SI to perform a new iteration of measurement and quantity testing in relation to steps SI and S2 described above.

[0037] But if at step S2 the current ISci is greater than or equal to the first predetermined threshold value without however reaching the second predetermined threshold value from which the rupture zone lOOf could begin to melt, then the control device 104 operates a current generation between terminals 108a and 108b, in the coil 108, so as to increase the magnetic field B to which the superconducting power supply line 100 is subjected, so as to increase its resistance and thus reduce the value of the current ISC1.

[0038] According to one embodiment, the controller device 104 reads a value of the second current ISc2 to be generated according to a table stored in a non-volatile memory which it integrates, from the value of the first current ISCi or from information representative of the value of the first current ISCL H. It should be noted that here, "current value", "current intensity" or "value of the current intensity" refers interchangeably to an intensity of electric current flowing in a conductive or superconducting element.

[0039] According to one embodiment, when the first current ISci reaches the second predetermined threshold value for a predetermined duration Tl, the melting rupture zone lOOf melts and opens the superconducting power supply line 100 during a step S4 subsequent to step S3 which only occurs in the event of a failure or malfunction of the control circuit 10, in particular in the presence of a fault current in the superconducting power supply line 100.

[0040] According to one embodiment, the control circuit 10 is configured so that the magnetic field B is zero when the first current ISCi is less than the first current threshold value and so that the magnetic field B is progressively increased with an increase in the current ISCi when the first current ISCi is greater than the first current threshold value.

[0041] The [Fig.4] is a diagram illustrating an example of the internal architecture of the controller device 104 of the control circuit 10 of a superconducting power supply line, according to one embodiment.

[0042] According to the hardware architecture example shown in [Fig. 4], the controller device 104 for the superconducting power supply line 100 then comprises, connected by a communication bus 1040: a processor or CPU (Central Processing Unit) 1041; a RAM (Random Access Memory) Memory (in English) 1042; a ROM (Read Only Memory) 1043; a storage unit such as a hard disk drive (or a storage media reader, such as an SD (Secure Digital) card reader) 1044; at least one interface module 1045 enabling the controller device 104 to interact with devices present in the control circuit 10, such as, for example, the current sensor 102 and the coil 108. Advantageously, the interface module INTER 1065 includes, in particular, input / output ports, inputs for digital-to-analog converters and analog-to-digital converters, pulse-width modulation controlled outputs, and more generally all types of interfaces, including power interfaces, particularly useful for measuring current in a superconducting power supply line and for generating current in a superconducting electric coil.In particular, the INTER 1065 interface module of the controller device 104 is configured to operate, among other things, electrical current monitoring and electrical current generation functions.

[0043] The processor 1041 is capable of executing instructions loaded into RAM 1042 from ROM 1043, external memory (not shown), storage media (such as an SD card), or a communication network. When the device 104 is powered on, the processor 1041 is capable of reading program code instructions from RAM 1042 and executing them. These instructions form a computer program causing the processor 1041 to implement all or part of a method described in relation to [Fig. 3], or all or part of the described variants of that method.

[0044] 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) or a microcontroller, or implemented in hardware form by a dedicated machine or component, for example a FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit). In general, the superconducting power supply line controller device 104 comprises electronic circuitry configured to implement the methods described in relation to the control circuit 10 or the controller device 104.Obviously, the superconducting power supply line controller 104 device 100 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, related input / output ports, interrupt inputs, bus drivers, this list being non-exhaustive.

[0045] Figure 5 illustrates an aircraft 1 advantageously comprising the control circuit 10 of a superconducting power supply line as previously described, which circuit includes the controller device 104. The use of such a system on board an aircraft comprising superconducting components makes it possible to offer an increased level of safety in the event of a fault in an onboard electrical distribution network. Furthermore, it is advantageously possible to adapt the first threshold value of the first ISCi current according to different flight phases of the aircraft 1. For example, the first threshold value during takeoff of the aircraft 1 can be higher than the first threshold value during a cruise or descent phase of the aircraft 1.

Claims

1.

2. Demands Method for controlling a superconducting power supply line (100), the method being carried out in a control circuit (10) of said power supply line and comprising the steps: - i) obtain (SI) information representative of a first electric current in said superconducting power supply line, - ii) compare said information representing a first electric current in said superconducting power supply line with a first predetermined threshold value, - iii) if (S2) said information representing a first electric current is greater than or equal to the first predetermined threshold value, generate (S3) a current, said second current, in a superconducting coil arranged near said superconducting power line and configured to emit a magnetic field, said superconducting power line being configured to receive said magnetic field, the value of said second current being determined from said information representing said first current, said method being characterized in that it further comprises a melting step (S4) of a calibrated rupture zone (lOOf) of said superconducting power line (100) when said first electric current has an intensity greater than a second predetermined threshold value for a predetermined time. Control circuit (10) of a superconducting power line (100), the control circuit comprising electronic circuitry configured to: - i) obtain representative information of a first electric current in said superconducting power supply line, - ii) compare said information representative of a first electric current in said supply line superconducting electrical with a first predetermined threshold value, and for, - iii) if said information representing a first electrical current is greater than or equal to a predetermined threshold value, generating a second current in a superconducting coil arranged near said superconducting electrical supply line and configured to emit a magnetic field, said superconducting electrical supply line being configured to receive said magnetic field, the value of said second current being determined from said information representing said first current,said control circuit of a superconducting power supply line (100) being characterized in that it further comprises a calibrated break zone (lOOf) of said superconducting power supply line configured to melt when said first electric current exceeds a second predetermined threshold value for a predetermined time.

3. Control system for a superconducting power supply line comprising a control circuit (10) according to claim 2 and a superconducting coil (108) powered by said control circuit (10) and arranged in close proximity to said superconducting power supply line (100).

4. Aircraft (1) comprising at least one control circuit (10) of a superconducting power line (100) according to claim 2 or a control system according to claim 3.

5. Product computer program comprising program code instructions to execute the steps of the process according to claim 1, when said program is executed by a processor (104) of a control circuit (10) of a superconducting power supply line (100).

6. Storage medium comprising a computer program product according to claim 5.

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