IMPROVED CONTROL FOR THE POWER SUPPLY CIRCUIT OF A SUPRAL CONDUCTING MOTOR, SUPRAL CONDUCTING POWER SUPPLY SYSTEM OF A MOTOR AND AIRCRAFT WITH SUCH A SYSTEM

Description

TECHNICAL FIELD

[0001] The present invention relates to a so-called superconducting motor, particularly of the type usable for aircraft propulsion. More specifically, the invention relates to the monitoring and control of a superconducting power supply link for an aircraft electric motor powered by an inverter, and 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] Using liquid hydrogen as an energy source for aircraft is a promising avenue. Hydrogen 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 can be used to enhance the performance of electrical equipment by lowering its resistivity and thus reducing Joule heating losses. Superconducting components can also be used. Superconducting conductors can be used 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 link between the inverter and the motor must be protected against an unexpected transition from the superconducting state to the conventional state (a transition usually referred to as . quench in the field of superconductivity). It is therefore important to be able to detect precursor signs of such a transition in order to avoid excessive losses due to the Joule effect which could damage the electrical power supply circuits and their immediate environment.

[0004] The detection of quench The detection of a superconducting conductor is generally carried out by monitoring the voltage across its terminals and detecting the appearance of an increase in the voltage level across its terminals. If the detection of a quench Detecting impedance on a direct current (DC) connection is fairly straightforward, as it involves distinguishing between zero and non-zero impedance (i.e., resistance) in the conductor. However, this is not the case for an alternating current (AC) connection. In the latter case, the inductive component of the impedance is never zero and is even greater than the resistive component in most cases, which disrupts or even prevents detection of the impedance. quench using conventional methods. Therefore, there is a need for a reliable solution that eliminates the inductive effect on the voltage across the conductor(s) of the motor's electrical supply link.

[0005] The document "Voltage-Based Current-Compensation Converter Control for Power Electronic Interfaced Distribution Networks in Future Aircraft" by Steven Nolan, Catherine E. Jones, Rafael Peña-Alzola, Patrick J. Norman, Graeme Burt, Paul Miller and Mark Husband, discloses a method for controlling and managing power in an electrical distribution network according to the prior art.

[0006] The situation can be improved. DESCRIPTION OF THE INVENTION

[0007] One object of the present invention is to provide a power supply circuit controller for an electric motor powered by alternating current, capable of quickly and reliably detecting the occurrence of a phenomenon of the type quench in a power supply link to a motor, so as to limit the current(s) delivered to the motor by an inverter when the power supply link between the inverter and the motor is about to transition from a nominal superconducting state to a state in which its resistivity increases.

[0008] To this end, a method is proposed for controlling the power supply circuit of an electric motor, the power supply circuit comprising a power converter, called an inverter, configured to deliver at least one alternating voltage from a direct current voltage source, and a superconducting power link configured to supply the electric motor, the superconducting power link being connected between an output of the inverter and the electric motor, the method being carried out in a power supply circuit controller comprising a control output configured to control the inverter, at least one first input configured to receive at least one first signal representative of a voltage measured across the terminals of the superconducting power link, and a second input, called a synchronization input, configured to receive at least one second signal representative of the position of the electric motor rotor, the method comprising: i) multiply the first signal and a sinusoidal signal synchronized with the second signal to obtain a third signal representative of the resistive component of the voltage measured across the terminals of the superconducting power supply link, then, ii) if the third signal exceeds a predetermined threshold value, inhibit the control output, and otherwise, repeat steps i) and ii).

[0009] Advantageously, this makes it possible to reliably and quickly detect, with limited resources, the emergence of a phenomenon of quench in a superconducting power supply link of an alternating current powered electric motor.

[0010] According to one embodiment, in the method of controlling a power supply circuit, obtaining said third signal includes low-pass filtering of a result of multiplying said first signal with said second signal.

[0011] The invention also relates to a power supply circuit controller for an electric motor, the power supply circuit comprising a power converter, referred to as an inverter, configured to deliver at least one alternating voltage from a direct current voltage source and a superconducting power link configured to supply the electric motor, the superconducting power link being connected between an output of the inverter and the electric motor, the power supply circuit controller comprising a control output configured to control the inverter, at least one first input configured to receive at least one first signal representative of a voltage measured across the terminals of the superconducting power link, and a second input, referred to as a synchronization input, configured to receive at least one second signal representative of the position of a rotor of the electric motor,the power supply circuit controller device comprising electronic circuitry configured for: , i) multiply the first signal and a sinusoidal signal synchronized with the second signal to obtain a third signal representative of the resistive component of the voltage measured across the terminals of the superconducting power supply link, then, ii) if said third signal exceeds a threshold value, inhibit said control output, and otherwise, repeat steps i) and ii).

[0012] The control device according to the invention may also include the following characteristics, considered alone or in combination: The power supply circuit controller further includes a low-pass filtering circuit for the result of multiplying said first signal with said second signal to obtain said third signal. The electronic circuitry of the power supply circuit controller includes a microprocessor control unit configured to perform operations and processing on signals applied to said first and second inputs of said controller. The power supply circuit controller includes: ∘ a signal multiplier circuit comprising a multiplier output and two multiplier inputs, one of which, the first of said two multiplier inputs, is connected to said first input and the other, the second of said two multiplier inputs, is connected to an output of a controlled sinusoidal signal generator; ∘ a low-pass filter circuit with a controlled cutoff frequency.comprising a filtered signal output and a signal input to be filtered, which signal input to be filtered is connected to the multiplier output of the signal multiplier, and a cutoff frequency control input, which cutoff frequency control input is connected to an output of a frequency determination module; a control circuit comprising an input connected to the filtered signal output of the low-pass filter circuit, and a control output configured to enable or inhibit the transmission of a transmissible control signal to said control output of the power supply circuit controller. Said frequency determination module of the power supply circuit controller is configured to determine a rotational frequency of the electric motor from an electrical signal comprising pulses.applied to the second input, the controlled sinusoidal signal generator is configured to generate a sinusoidal signal of a determined frequency synchronized with a reference position of the electric motor rotor. The controlled cutoff frequency of the power supply circuit controller's low-pass filter is determined by the determined rotational frequency.

[0013] The invention also relates to an electric motor power supply system comprising a superconducting power link controller as described above.

[0014] The invention further relates to an aircraft comprising at least one superconducting power link controller as previously described or a system as previously described.

[0015] Finally, the invention relates to a computer program product comprising program code instructions to execute the steps of the process described when the program is executed by a processor of a power supply circuit controller, as well as a storage support device comprising such a program. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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: Fig. 1 schematically illustrates an electrical power supply circuit controller of an electric motor operating in an aircraft engine power supply system, according to one embodiment; Fig. 2 is a flowchart illustrating a method for controlling an electric power supply circuit of an electric motor, carried out in a controller of an aircraft engine power supply system, according to one embodiment; Fig. 3 schematically illustrates an electrical power supply circuit controller for an electric motor in an aircraft engine power supply system, according to an embodiment including the use of software functions; Fig. 4 schematically illustrates an electrical power supply circuit controller for an electric motor in an aircraft engine power supply system, according to an embodiment including, in particular, circuits and hardware modules; Fig. 5 schematically illustrates an example of the internal architecture of the power supply circuit controller already shown on the Fig. 1 And Fig. 3 ; And, Fig. 6 illustrates an aircraft comprising an electrical power system including an electrical power circuit controller according to one embodiment. DETAILED EXPLANATION OF IMPLEMENTATION METHODS

[0017] There Fig. 1 This is a schematic representation of a power supply system 10 configured to electrically supply an electric motor 100, according to one embodiment. In the example described here, the electric motor 100 is an aircraft engine. To achieve this, the power supply system 10 includes a power circuit controller 106 for controlling a power supply circuit comprising an inverter 102, which in turn supplies a superconducting power link 104 connected to the electric motor 100. The superconducting power link 104 is connected between an output of the inverter 102 and the electric motor 100. The inverter 102 operates as a power converter and provides a three-phase electrical network of voltages to the electric motor 100, via the superconducting power link 104, from a DC voltage source 101.The three-phase electrical network comprises a first power supply line 104a, a second power supply line 104b and a third power supply line 104c. These three power supply lines together make up the superconducting power link 104.

[0018] In order to control the power supply circuit of the electric motor 100, the power supply circuit controller 106 includes at least: a CTRL current control output configured to control the current of the inverter 102, a first input, Vi, configured to receive a signal representative of a voltage measured across the terminals of the superconducting power link 104, and, a second input, θ, called the synchronization input pin, configured to receive at least one information representative of the position of the rotor of the electric motor 100, from the electric motor 100, via a connection link 108.

[0019] The control of the inverter 102 by the power supply circuit controller 106 uses a connection link 107. According to one embodiment, the connection link 107 carries a pulse width modulation (PWM) type signal generated by control circuits and modules operating a vector control type control of the inverter.

[0020] According to one embodiment, the three supply lines 104a, 104b, and 104c of the superconducting power link 104 are arranged in the same cryogenic volume, and only one of them is subject to voltage measurement between its ends by a potential difference determination module 110, the output of which is connected to the input Vi of the power supply circuit controller 106 via a connecting link 109. According to this configuration, and in the event of a loss of cryogenic fluid causing a temperature increase in the superconducting power link 104, the single detection of an increase in potential difference on the supply line connected to the potential difference determination module 110 is sufficient to perform a detection of quench and to define subsequent operations useful for the preservation of the systems.

[0021] According to one embodiment, the potential difference determination module 110 includes internal multiplexing circuits to operate a sequential scanning (monitoring) of the potential differences between the two ends of each of the power supply lines 104a, 104b and 104c, successively and iteratively.

[0022] According to one embodiment, each of the power supply lines 104a, 104b and 104c is associated with a potential difference determination module such as module 110, and the control and monitoring circuits described below are reproduced for each of the power supply lines 104a, 104b and 104c so as to detect a phenomenon of quench as soon as possible on one of the power supply lines 104a, 104b and 104c of the power supply link 104. An "OR" type logic is then used at the output of these three identical or similar circuits to inhibit or modify the inverter control in the presence of a phenomenon quench on any one of the three power supply lines 104a, 104b and 104c of the superconducting power supply link 104. The connecting links between one of the respective ends of the power supply lines 104a, 104b and 104c and the potential difference determination module 110 form a bus 104u. The connecting links between the other of the respective ends of the power supply lines 104a, 104b and 104c and the potential difference determination module 110 form a bus 104d.

[0023] Cleverly and advantageously, the power supply circuit controller 106 performs processing and operations based on potential difference information measured across at least one of the power supply lines 104a, 104b, and 104c, via the potential difference determination module 110 and its input Vi, on the one hand, and on the position of the electric motor 100's rotor, obtained via its input θ, to discriminate the resistive component of the voltage measured across at least one of the power supply lines of the supply link 104, on the other. To accomplish this, the power supply circuit controller 106 includes electronic circuitry configured to: i) multiply the signal available at input Vi with a sinusoidal signal synchronized with said signal available at input θ to obtain a signal resulting from the multiplication, representative of the resistive component of the voltage measured across the terminals of the superconducting power supply link 104, and, electronic circuitry configured for: ii) if the signal resulting from the multiplication exceeds a predetermined threshold value, inhibit the inverter control CTRL output 102 and otherwise, repeat steps i) and ii).

[0024] According to one embodiment, the electronic circuitry is configured to inhibit the control CTRL output of the inverter 102 only if the signal resulting from the multiplication performed exceeds the predetermined threshold value for at least a predetermined threshold duration or for a duration exceeding this threshold duration.

[0025] The terms "inhibit the inverter control output" herein refer to any operation subsequent to the detection of the crossing of the threshold value (where applicable for a duration equal to or exceeding a threshold duration) and aimed at limiting the thermal dissipation by Joule effect in the superconducting power link 104, by limiting the current delivered by the inverter 102 in each of the power supply lines 104a, 104b and 104c or by interrupting the operation of the inverter 102.

[0026] In one embodiment, disabling the CTRL output defines a degraded operating mode for the inverter 102, at reduced power. In another embodiment, disabling the CTRL output isolates the DC voltage source 101 from the inverter 102. These embodiments are not exhaustive, and other methods of controlling the power dissipated in the power supply link 104, via the CTRL control output of the controller 102, can of course be implemented.

[0027] There Fig. 2 is a flowchart-type diagram that illustrates the steps of a process for controlling the power supply link 104 of the electrical power supply system 10 of the electric motor 100, executed by the power supply circuit controller 106, according to one embodiment. A step S0includes 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 electric motor 100 and its power supply circuit 10.

[0028] One step S1 includes obtaining, by the power supply circuit controller 106, via its input Vi, a potential difference measured between the ends of at least one power supply line among the power supply lines 104a, 104b and 104c of the superconducting power supply link 104. A step S2This includes obtaining, via its input θ, the position of the motor 100 rotor by the power supply circuit controller 106, and synchronizing a sinusoidal signal generated internally by the power supply circuit controller 106 with a predetermined rotor position θ1. This isolates the purely resistive component of the voltage measured across one or more power supply lines of the power supply link 104 (which is synchronized with the fundamental component of the current injected into the electric motor 100) and eliminates any interference related to the inductive component of this voltage. More specifically, step S2 provides information on the sine of the angular position of the motor 100 rotor. Steps S1 and S2 are performed in parallel, i.e., simultaneously.Cleverly, the two quantities thus obtained, namely a first piece of information representing a potential difference measured between the ends of the supply link 104 and a second piece of information representing the sine of the angular position of the rotor of the motor 100, are multiplied during a step. S3 in order to achieve improved detection of a phenomenon of quench adapted to a three-phase alternating current supply of the electric motor 100.

[0029] An optional step S4 Low-pass filtering can be performed to filter the result of the multiplication, and then a comparison of the result of the multiplication, or where applicable, of this result filtered by a low-pass filter, is compared to a predetermined threshold value, during a step S5.The result of step S4 allows us to obtain the resistive component of the supply link 104. Such a low-pass filtering operation is, however, optional. In the case where the value compared with the threshold value exceeds the predetermined threshold value, and therefore in the presence of a phenomenon of quench, The CTRL control output of inverter 102 is inhibited during a step S6 so as to preserve the integrity of the power supply systems of the electric motor 100 present. Otherwise, and therefore in the absence of the phenomenon of quench Upon detection in the superconducting power supply link 104, the power supply circuit controller 106 loops back to steps S1 and S2 to perform a further iteration of the process steps described above. Optionally, during step S5, and after detection of an exceedance of the predetermined threshold value, it is verified that the exceedance is detected for at least a predetermined duration to allow the inhibition operations of step S6. Otherwise, if the exceedance of the predetermined threshold value occurs only for a time shorter than the predetermined threshold duration and is subsequently resolved, the process continues sequentially by looping back from steps S1 and S2. In one embodiment, such a point-based detection triggers a configuration of monitoring and control systems for the power supply circuit 10 of the motor 100.

[0030] In one embodiment, the predetermined threshold value against which the result of the multiplication performed in step S3 is compared is predetermined by calculation, operational testing in a research laboratory, or validation and / or type-approval testing. The same applies to the threshold duration value, if applicable. In one embodiment, these two values ​​are programmable, preferably remotely via a remote control interface of the power supply circuit controller 106.

[0031] The steps of the process described above can be implemented interchangeably by hardware circuitry, by software functions, or by a combination of these two forms of implementation.

[0032] There Fig. 3 represents the main modules of the power supply circuit controller 106, implemented in hardware or software form, or a combination thereof. The input Vi of the power supply circuit controller 106 is configured to receive information representative of the potential difference present between opposite ends of the supply lines 104a, 104b, and 104c, via the connection link 109. The three-phase electrical potential measurement links 104u and 104d connect the upstream and downstream ends of the superconducting electrical supply link 104, respectively, to the potential difference determination module 110. The potential difference determination module 110 includes synchronized multiplexing means for connecting the different supply lines of the link 104u and the link 104d to its internal potential difference determination circuits.The potential difference determination module 110 is further configured to deliver, via the connection link 109, information in the form of a signal, which information is representative of the potential differences present between the ends (or terminals) of each of the supply lines 104a, 104b or 104c of the superconducting power supply link 104. The potential difference determination module 110 may include digital electronic circuitry, analog electronic circuitry or a combination of these two types of electronic circuitry to perform these functions of determining the voltages across the terminals of the superconducting power supply link 104, or more precisely a quantity representative of the impedance of one or more supply lines of the superconducting power supply link 104.

[0033] In one embodiment, the synchronization input θ is connected to a position synchronization output of the electric motor 100 via a connecting link 108, and carries a signal representing both the motor's rotational speed and the rotor's position relative to a predefined rotor reference position. In another embodiment, the connecting link 108 comprises several independent signals for encoding this information.

[0034] The CTRL control output of the power supply circuit controller 106 delivers, via the connection link 107, pulse-width modulation modulated signals to a switching control input of the inverter 102. According to the example described, the output of the inverter 102 is current-controlled from the CTRL control output of the controller 106.

[0035] According to one embodiment, the power supply circuit controller 106 comprises three outputs CTRL1, CTRL2 and CTRL3, each dedicated to one of the supply lines (phase) of the three-phase superconducting power supply link 104, and a complete phenomenon detection system. quench is implemented for each of the power lines 104a, 104b, and 104c of the superconducting power link 104, in the power circuit controller 106.

[0036] In this description, the terms "connecting link" and "signal" are used interchangeably. For example, the synchronization signal representing the position of the rotor of the electric motor 100, carried by the connecting link 108, is further referred to as signal 108. Similarly, the signal representing an electrical potential difference delivered by the module 110, and carried by the connecting link 109, is further referred to as signal 109, and the current control signal, carried by the connecting link 107, is further referred to as signal 107.

[0037] The principle of detecting a phenomenon of quench is described here in relation to the superconducting power link 104a. In one embodiment, the same principle is applied to the superconducting power links 104b and 104c, using means similar to those implemented for the superconducting power link 104a. Regarding the internal electronic circuitry of the power supply circuit controller 106, composed of the inverter 102 and the power link 104, the synchronization signal 108 delivered by the synchronization output of the electric motor 100 is applied to a motor speed determination and sinusoidal signal generation module 1080, also called the speed determination and sinusoidal signal generation module 1080. The module 1080 is specifically configured to generate sinusoidal signals controlled and synchronized with the position of the rotor of the electric motor 100.Synchronized signals with an angular reference position of the rotor are delivered via a connecting link 1081a. Cleverly, a synchronized sinusoidal signal 1081a is applied, via a connecting link 1081b, to one input of a multiplier circuit 1085, the other input of which is connected to the signal 109 representing the potential difference between the ends of the supply line 104a, or another supply line if applicable. Multiplying this synchronized sinusoidal signal with the resistive component and a quantity proportional to a potential difference measured between the ends of the superconducting supply line 104a advantageously provides, at an output 1086 of the multiplier 1085, information representing the absence or presence of a phenomenon. quench in the superconducting link 104. This information, presented as a signal containing a DC component of interest and a component with a frequency equal to twice the frequency of the quantities present in the link 104, is then optionally filtered by a low-pass filter circuit (not shown in the diagram). Fig. 3 ) at a controlled cutoff frequency to obtain information of even better quality, representative of the absence or presence of a phenomenon of quench in the superconducting link 104. The signal 1086, optionally filtered by a low-pass filter circuit, is then applied to a control circuit 1089 configured to inhibit the current control CTRL output of the inverter 102 in the presence of a problem such as, for example, a phenomenon of quench. The 1089 control circuit is configured to detect a phenomenon of quench, as previously described, and can be further configured to detect a temperature problem or a current problem, for example. More broadly, the control circuit 1089 is configured to perform monitoring and protection functions for the superconducting power supply circuit 10. In one embodiment, a signal available at an output 107f of the control circuit 1089 is applied to a control output (or controlled output) configured to enable or inhibit the transmission of a control signal 107c to the CTRL output pin of the power supply circuit controller 106, via an output control circuit 107g. Thus, the control signal 107c to the CTRL output pin is determined, for example, by a vector control signal primarily implemented by a control module 1070.According to the embodiment described here, signal 107 is therefore identical to signal 107c when the output control circuit is not activated by control circuit 1089 to inhibit the current control of inverter 102. Control module 1070 is configured to perform motor torque control and to determine a CTRL control signal, notably from a signal 1081c which corresponds to a torque setpoint. This signal is also dependent on the angular position θ of the electric motor 100. The implementation details of the vector control operated by the power supply circuit controller 106 are independent of the circuits specific to the detection of... quench described previously, are not described here in more detail insofar as they are known to a person skilled in the art of inverter control and insofar as they are not useful for a proper understanding of the invention.

[0038] The clever use of a multiplier circuit such as the 1085 multiplier circuit to obtain information representative of a phenomenon of quench based on the potential difference measured between the ends of the superconducting power supply link 104 on the one hand, and the angular position θ of the rotor of the electric motor 100 on the other hand, it is therefore advantageous to perform a rapid and reliable detection of the occurrence of a phenomenon of quench, which can be all the more reliable as the signal obtained at the output of the multiplier circuit 1085 can be filtered by a low-pass filter circuit whose cutoff frequency depends on the rotation frequency of the electric motor 100. Advantageously, the cutoff frequency of the low-pass filter used is determined as a function of the rotation frequency of the electric motor 100.

[0039] The use of a power supply circuit controller with the internal architecture of the power supply circuit controller 106, or an equivalent architecture operating the same functions, advantageously allows control of the electrical power supply to the motor 100 to avoid degradation or even destruction of the superconducting link 104 when the conditions for proper operation are no longer met.

[0040] There Fig. 5 is a diagram illustrating an example of the internal architecture of the power supply circuit controller 106, according to one embodiment. For illustrative purposes, consider that the Fig. 5 illustrates an internal arrangement of the power supply circuit controller 106. Note that the Fig. 5 could also schematically illustrate an example of hardware architecture of a processing module included in the power supply circuit controller 106, in addition to other modules configured to operate other functions.

[0041] According to the example of hardware architecture shown in the Fig. 5 The power supply circuit controller 106 then comprises, connected by a communication bus 1060: a processor or CPU (Central Processing Unit) 1061; a RAM (Random Access Memory) 1062; a ROM (Read Only Memory) 1063; a storage unit such as a hard disk drive (or a storage media reader, such as an SD card reader (Secure Digital) 1064); at least one interface module 1065 enabling the power supply system controller 106 to communicate with devices present in the power supply system 10, such as, for example, the inverter 102, the potential difference determination module 110 and the electric motor 100.Advantageously, the INTER 1065 interface module includes input / output ports, digital-to-analog and analog-to-digital converter inputs, pulse-width modulation controlled outputs, and more generally, all types of interfaces useful for managing a motor power supply system using a three-phase current source such as an inverter operating from a DC power source. In particular, the INTER 1065 interface module of the 106 controller is configured to operate, among other things, vector control functions of an inverter such as the 102 inverter.

[0042] The 1061 processor is capable of executing instructions loaded into RAM 1062 from ROM 1063, external memory (not shown), storage media (such as an SD card), or a communication network. When the power supply circuit controller 106 is powered on, the 1061 processor can read program code instructions from RAM 1062 and execute them. These instructions form a computer program that causes the 1061 processor to implement all or part of a process described in relation to the Fig. 2 , or of all or part of the described variants of this process.

[0043] All or part of the process described in relation to the Fig. 2 The described process, or its variants, can be implemented in software form by a programmable machine, such as a DSP (Digital Signal Processor) or a microcontroller, executing a set of instructions, or in hardware form by a dedicated machine or component, such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit). In general, the power supply circuit controller 106 includes electronic circuitry configured to implement the processes described in relation to the power supply circuit controller 106.Obviously, the 106 power supply circuit controller 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.

[0044] There Fig. 4 This illustrates another example of the implementation of the power supply circuit controller 106. According to this embodiment, the internal electronic circuits of the power supply circuit controller 106 are all implemented in hardware. The synchronization signal 108 delivered by the synchronization output of the electric motor 100 is applied to a motor speed-determining module 4080s, also called the frequency-determining module 4080s, via the input θ and through an internal connection link 408 connected to the connection link 108. The synchronization signal 408 is further applied to a controlled sinusoidal signal generator module 4080g. Sinusoidal signals can then be generated in sync with the angular position θ of the rotor of the electric motor 100.Cleverly, a synchronized sinusoidal signal 4081a is applied, via a connecting link 4081b, to one input of a multiplier circuit 4085, the other input of which is connected to the signal 409, linked to the external connecting link 109 via the input Vi, and representative of the potential difference present between the ends of the superconducting power link 104a, or, by multiplexing, of the power line 104b or the power line 104c. Here again, the multiplication of a sinusoidal signal synchronized with the resistive component of the voltage across the power link, and of a quantity proportional to a potential difference measured between the ends of the superconducting power line 104a, makes it possible to have, on an output 4086 of the multiplier 4085, information representative of the absence or presence of a phenomenon. quench in the superconducting link 104. This information, present as a signal containing a DC component of interest and a component with a frequency twice that of the quantities in the supply link 104, is then filtered by a low-pass filter circuit 4087 with a controlled cutoff frequency to obtain other, even more reliable information, because it is free of high-frequency disturbances, representative of the absence or presence of a phenomenon of quench in the superconducting power supply link 104. The low-pass filter circuit 4087 includes a cutoff frequency control input 4082b, which input 4082b is connected to an output 4082a of the frequency determination module 4080s. This advantageously enables a tuned "low-pass" type filtering whose cutoff frequency depends on the rotational speed of the electric motor 100's rotor. Measurement disturbances inherent in the fact that the inductive component of the quantities present is generally much greater than the resistive component of these same quantities are thus avoided. The signal filtered by the low-pass filter circuit 4087, available at its output, is then applied, via a connection link 4088, to a control circuit 4089 configured to inhibit the current control CTRL output of the inverter 102 in the presence of a problem such as, for example, a phenomenon of quench. The 4089 control circuit is configured to detect a phenomenon of quench, as previously described, and can be further configured to detect a temperature problem or a current problem, for example. More broadly, the 4089 control circuit is configured to perform monitoring and protection functions for the superconducting power supply circuit. Specifically, a signal available at the 407f output of the 4089 control circuit is applied to a control output (or controlled output) configured to enable or inhibit the transmission of a 407c control signal to the CTRL output pin of the power supply circuit controller 106, via a 407g controlled output circuit. Thus, the 407c control signal transmitted to the CTRL output pin is determined, for example, by a vector control.Signal 107 is therefore identical to signal 407c when the controlled output circuit 407g is not activated by the control circuit 4089 to inhibit the current control of the inverter 102. A motor torque control circuit 4070 determines a CTRL control signal from a signal 4084, which corresponds to the torque setpoint, and signal 4081c, which represents the angular position of the electric motor 100. The torque setpoint signal 4084 is delivered by a speed control circuit 4083, which operates from the module 4080s that determines the rotational speed of the electric motor 100.

[0045] There Fig. 6 illustrates an aircraft 1 comprising the electrical power system 10 described above, which system includes the controller 106. The use of such a system on board an aircraft propelled by at least one electric motor such as the electric motor 100 provides an increased level of safety in the event of the occurrence of a phenomenon of quench on a motor's power supply link.

[0046] The clever use of a rotor positioning measurement θ of the electric motor advantageously eliminates the need for a PLL (phase-locked loop) circuit to differentiate between the resistive and inductive components of the electrical quantities present. Indeed, using a PLL circuit is complex and sensitive in a noisy environment such as the power supply link of an electric motor.

[0047] In addition, the clever use of a low-pass filter circuit with a cutoff frequency controlled according to the motor's rotation frequency makes it possible to obtain a compromise between the signal bandwidth for which protection is implemented and the rejection of higher-frequency parasitic signals, in particular the component at twice the operating frequency inherent in the multiplication performed by the module or multiplier circuit.

[0048] Finally, an implementation according to the described embodiments advantageously allows for a significant increase in the level of security while remaining simple and requiring very limited additional hardware resources.

Claims

1. Method for controlling a power supply circuit (102, 104) of an electric motor (100), the power supply circuit (102, 104) comprising a power converter (102), referred to as an inverter (102), which is configured to supply at least one AC voltage from a DC voltage source (101) and a superconducting power supply link (104), which is configured to supply said electric motor (100) with power, the superconducting power supply link (104) being connected between an output of the inverter (102) and the electric motor (100), said method being executed in a power supply circuit controller (106) comprising a control output (CTRL) configured to control said inverter (102), at least one first input (Vi) configured to receive at least one first signal representative of a voltage measured across the terminals of said superconducting power supply link (104), and a second input (θ), referred to as a synchronization input, configured to receive at least one second signal representative of the position of a rotor of said electric motor (100), said method being characterized in that it comprises: - i) multiplying said first signal and a sinusoidal signal synchronized with said second signal to obtain a third signal that is representative of the resistive component of said voltage measured across the terminals of said superconducting power supply link (104), and then, - ii) if said third signal exceeds a predetermined threshold value, inhibiting said control output (CTRL), and if not, repeating steps i) and ii).

2. Method for controlling a power supply circuit (102, 104) according to Claim 1, wherein obtaining said third signal comprises low-pass filtering a result of the multiplication of said first signal with said second signal.

3. Controller device (106) for a power supply circuit (102, 104) of an electric motor (100), said power supply circuit (102, 104) comprising a power converter (102), referred to as an inverter (102), which is configured to supply at least one AC voltage from a DC voltage source (101) and a superconducting power supply link (104), which is configured to supply said electric motor (100) with power, the superconducting power supply link (104) being connected between an output of the inverter (102) and the electric motor (100), said controller device (106) for a power supply circuit comprising a control output (CTRL) configured to control said inverter (102), at least one first input (Vi) configured to receive at least one first signal representative of a voltage measured across the terminals of said superconducting power supply link (104), and a second input (θ), referred to as a synchronization input, configured to receive at least one second signal representative of the position of a rotor of said electric motor (100), said controller device (106) for a power supply circuit being characterized in that it comprises electronic circuitry that is configured to: - i) multiply said first signal and a sinusoidal signal synchronized with said second signal to obtain a third signal that is representative of the resistive component of said voltage measured across the terminals of said superconducting power supply link (104), and then, - ii) if said third signal exceeds a threshold value, inhibit said control output, and if not, repeat steps i) and ii).

4. Controller device (106) according to Claim 3, further comprising a circuit for low-pass filtering a result of the multiplication of said first signal with said second signal to obtain said third signal.

5. Controller device (106) according to Claim 3, wherein said electronic circuitry comprises a microprocessor-based control unit.

6. Controller device (106) according to either of Claims 3 and 4, the controller device (106) comprising: - a signal multiplier circuit (4085) comprising an output (4086) and two inputs (409, 4081b), one of which, the first (109) of said two inputs, is connected to said first input (Vi) and the other of which, the second (4081b) of said two inputs, is connected to an output of a controlled sinusoidal signal generator (4080g), - a low-pass filter circuit (4087) with a controlled cut-off frequency, comprising a filtered signal output (4088) and an input for a signal to be filtered, which input is connected to said output (4086) of said signal multiplier (4085), and a cut-off frequency control input (4082b), which input is connected to an output (4082a) of a frequency determination module (4080s), - a command circuit (4089) comprising an input (4088) connected to said output (4088) of said low-pass filter circuit (4087), and a command output (407f, 407g) that is configured to validate or inhibit the transmission of a command signal (407c) that is able to be transmitted to said control output (CTRL).

7. Controller device (106) according to the preceding claim, wherein said frequency determination module (4080s) is configured to determine a frequency of rotation of said electric motor from an electrical signal (408), comprising pulses, that is applied to said second input (θ) and said controlled sinusoidal signal generator (4080g) is configured to generate a sinusoidal signal of determined frequency that is synchronized with a reference position of the rotor of the electric motor (100).

8. Controller device (106) according to Claim 7, wherein said controlled cut-off frequency of said low-pass filter (1087) is determined by way of said determined frequency of rotation.

9. System (10) for supplying electrical power to an electric motor (100), comprising a controller device (106) for a power supply circuit (102, 104) of an electric motor (100) according to one of Claims 3 to 8.

10. Aircraft (3) comprising at least one controller device (106) for a power supply circuit (102, 104) of an electric motor (100) according to one of Claims 3 to 8.

11. Aircraft (3) comprising at least one system (10) for supplying electrical power to an electric motor (100) according to Claim 9.

12. Computer program product comprising program code instructions for executing the steps of the method according to either of Claims 1 and 2, when said program is executed by a processor of a power supply circuit controller.

13. Storage medium comprising a computer program product according to the preceding claim.