Power converter, in particular for an aircraft, and associated methods

Abstract

The invention relates to an electrical power converter (2) for supplying power to an electric load (3), in particular of an aircraft (1), comprising - a supply module (5); - at least one main switching arm (18, 19, 20) comprising a first main switch (21) and a second main switch (22); - at least one intermediate connection (29, 30, 31) arranged between the first main switch (21) and the second main switch (22) and intended to be connected to one phase (35, 36, 37) of the electric load (3); - an auxiliary circuit (7) comprising at least one control line (41, 42, 43) comprising at least one switching cell (44, 45, 46). The switching cell (44, 45, 46) comprises at least one auxiliary switch (62), particularly an auxiliary switch (62) made of silicon carbide or of gallium nitride.

Description

[0001] DESCRIPTION

[0002] TITLE: Power converter, particularly for an aircraft, and associated methods

[0003] Technical field of the invention

[0004] The invention relates to electrical power converters, in particular for an aircraft, and more particularly to electrical power converters using power components made of silicon carbide (SiC) or gallium nitride (GaN).

[0005] The invention further relates to an aircraft comprising such a power converter, and a method for supplying an electrical load, in particular of the aircraft, by such a power converter.

[0006] State of the prior art

[0007] Typically, an aircraft includes an electrical power converter driving an electrical load, for example a three-phase fuel pump of the aircraft, from a direct voltage delivered by an aircraft bus.

[0008] The power converter delivers a variable three-phase voltage system to the electrical load in order to regulate the power supplied to the electrical load. Thus, if the electrical load is a pump, the power converter delivers a variable three-phase voltage system to the pump in order to regulate the power supplied to the pump and in order to regulate its rotation speed.

[0009] In order to obtain the three-phase voltage system from the DC voltage supplied by the bus, the power converter implements silicon switching power components to generate two voltage levels (also referred to as a three-phase two-level voltage converter). Silicon switching power components generally include metal oxide semiconductor field effect transistors, also known by the acronym MOSFET for "Metal Oxide Semiconductor Field Effect Transistor" in English, or insulated gate bipolar transistors, also known by the acronym IGBT for "Insulated Gate Bipolar Transistor" in English.

[0010] These proven transistor technologies are widely used in aircraft.

[0011] However, silicon switching power components generate significant thermal losses leading to an increase in their power consumption and an increase in the temperature of these components and neighboring components which can lead to a reduction in the lifetime of these components and neighboring components.

[0012] In addition, silicon power switching components have a large footprint, increasing the footprint of the power converter.

[0013] Wideband switching power components, also known by the acronym WBG for "Wide Band Gap" in English, made from silicon carbide (SiC) and gallium nitride (GaN), make it possible to overcome the limitations of silicon power switching components presented above.

[0014] However, these WBG type components have not yet been proven for aeronautical applications.

[0015] Statement of the invention

[0016] The aim of the invention is to overcome all or part of these drawbacks, in particular by integrating WBG type switching power components into a power converter while guaranteeing continuity of operation of the power converter in the event of failure of one of the WBG type components.

[0017] In view of the above, the subject of the invention is an electrical power converter for supplying an electrical load, in particular of an aircraft, comprising

[0018] - a power supply module, intended to be connected to a power source, in particular a continuous power source;

[0019] - at least one main switching arm comprising a first main switch and a second main switch, in particular an identical first main switch and a second main switch, respectively comprising a first end and a second end, the first end of the first main switch and the second end of the second main switch being connected to the power supply module and the second end of the first main switch being connected to the first end of the second main switch;

[0020] - at least one intermediate connection, arranged between the first main switch and the second main switch and intended to be connected to a phase of the electrical load;

[0021] - an auxiliary circuit comprising as many control lines as there are main switching arms, at least one control line comprising at least one switching cell comprising o a first end connected to the power supply module and o a second end connected to the intermediate connection, The switching cell comprises at least one auxiliary switch, in particular an auxiliary switch made of silicon carbide or gallium nitride.

[0022] The implementation of a wideband WBG silicon carbide (SiC) or gallium nitride (GaN) auxiliary switch makes it possible to reduce the size of the power converter and to reduce the thermal losses generated by the electrical power converter.

[0023] Preferably, the electrical power converter comprises a monitoring module configured to detect a failure or drift of the auxiliary switch from functional parameters of the auxiliary switch and to deactivate the auxiliary switch upon detection of a failure or drift of the auxiliary switch.

[0024] Advantageously, the power supply module comprises a power supply line comprising a first end and a second end intended to be connected to the power supply source and in which the power supply line comprises two impedances, in particular two identical impedances, in particular capable of being connected in series.

[0025] Preferably, the power supply module comprises an additional connection arranged between the two impedances and intended to be connected to the first end of the switching cell.

[0026] Advantageously, the electrical power converter comprises at least one auxiliary switching arm comprising a first secondary switch and a second secondary switch, in particular a first secondary switch and a second identical secondary switch, respectively comprising a first end and a second end, the second end of the first secondary switch being connected to the first end of the second secondary switch.

[0027] Preferably, a middle connection is provided between the first secondary switch and the second secondary switch and is connected to the first end of the control line switching cell.

[0028] Advantageously, the first end of the first main switch and / or the first secondary switch, and the second end of the second main switch and / or the second secondary switch are respectively connected to a different end of the power supply line. Preferably, the power supply module further comprises a selection switch comprising a control input, a first power input, a second power input and a power output, and configured to connect the power output to one of the power inputs according to a signal received on the control input.

[0029] Advantageously,

[0030] - the first power input is connected to the middle connection,

[0031] - the second power input is connected to the additional connection and

[0032] - the power output is connected to the first end of the control line switching cell.

[0033] Preferably, the first main switch, respectively the second main switch, is made of silicon carbide or gallium nitride.

[0034] Advantageously, the first secondary switch, respectively the second secondary switch is made of silicon.

[0035] Preferably, the first main switch, respectively the second main switch, comprises a transistor, in particular a double-gate transistor, in particular a double-gate transistor made of gallium nitride.

[0036] Advantageously, the auxiliary switch comprises at least a first transistor and a second transistor, in particular a first transistor and a second transistor made of gallium nitride, connected in series so that

[0037] - a source of the first transistor is connected to a drain of the second transistor, - a drain of the first transistor and a source of the second transistor are connected to a different end of the switching cell.

[0038] Such a series connection is common source. Alternatively, however, a common drain configuration could be considered.

[0039] An aircraft comprising an electrical power converter as defined above is also proposed.

[0040] A method of supplying electrical power to an electrical load, in particular for an aircraft, connected to an electrical power converter as defined previously is also proposed: comprising the control of the first main switch and the second main switch so as to supply one phase of the electrical load,

[0041] The method for supplying electrical power to an electrical load further comprises at least one step of detecting a failure or a drift of the auxiliary switch from functional parameters of the auxiliary switch, and a step of deactivating the auxiliary switch upon detection of a failure or a drift of the auxiliary switch.

[0042] Advantageously, the method for supplying electricity to an electrical load further comprises: a step of controlling the switching cell so as to supply the phase with three voltage levels as long as no failure or drift of the auxiliary switch has been detected, and a step of deactivating the auxiliary switch, controlling the first main switch and the second main switch so as to supply the phase with two voltage levels.Preferably, the method for supplying electricity to an electrical load further comprises: upon detection of the failure or drift of the first main switch and the second main switch, deactivation of the faulty or drifting switch, and as long as no failure or drift of the auxiliary switch has been detected, control of the switching cell and of the first secondary switch and / or of the second secondary switch so as to supply the phase of the load with two voltage levels, the controlled secondary switch replacing the faulty switch.

[0043] Of course, the different characteristics, variants and / or embodiments of the present invention can be associated with each other in various combinations to the extent that they are not incompatible or exclusive of each other.

[0044] Brief description of the drawings

[0045] The present invention will be better understood and other aims, characteristics and advantages of the invention will become apparent upon reading the detailed description which follows, comprising embodiments given solely for illustrative purposes with reference to the appended figures, presented as non-limiting examples, which may serve to complete the understanding of the present invention and the description of its embodiment and, where appropriate, contribute to its definition, and made with reference to the appended drawings in which:

[0046] [Fig 1] schematically illustrates an example of an aircraft according to the invention;

[0047] [Fig 2] illustrates an electrical diagram of a first embodiment of a power converter according to the invention;

[0048] [Fig 3] schematically illustrates an example of an auxiliary switch according to the invention; [Fig 4] schematically illustrates another example of an auxiliary switch according to the invention;

[0049] [Fig 5] schematically illustrates a second example of a power supply module according to the invention,

[0050] [Fig 6] illustrates an electrical diagram of a second embodiment of a power converter according to the invention,

[0051] [Fig 7] illustrates an electrical diagram of a third embodiment of a power converter according to the invention, and [Fig 8] schematically illustrates an embodiment of the main switching arm.

[0052] It should be noted that, in the figures, the structural and / or functional elements common to the different embodiments may have the same references. Thus, unless otherwise stated, such elements have identical structural, dimensional and material properties.

[0053] Detailed description of at least one embodiment

[0054] Reference is made to Figure 1 which schematically illustrates an example of an aircraft 1 comprising an electrical power converter 2, an electrical load 3, powered by the electrical power converter 2, and a power source 4, in particular a continuous power source 4, comprising, for example, a direct voltage electrical power supply bus for the aircraft 1. According to a specific example, the electrical load 3 may, for example, be a fuel pump.

[0055] Advantageously, the electrical load 3 is of the three-phase type so that the electrical power converter 2 delivers a three-phase voltage system to control the electrical load 3 from the direct voltage delivered by the power source 4.

[0056] Figure 2 illustrates an electrical diagram of a first exemplary embodiment of the electrical power converter 2 according to the invention. In the first exemplary embodiment, the electrical power converter 2 connected to the electrical load 3 and to the power source 4 delivering a voltage Ve, in particular direct voltage Ve, for example 540 V.

[0057] The electrical power converter 2 may include in particular a power supply module 5.

[0058] According to an exemplary embodiment, the power supply module 5 comprises two input terminals 8, 9, respectively a first input terminal 8 and a second input terminal 9, connected to the power supply source 4 so that the voltage Ve is applied between the input terminals 8 and 9. The power supply module 5 also comprises three output terminals 10, 11, 12, respectively a first output terminal 10, a second output terminal 11 and a third output terminal 12.

[0059] The power supply module 5 comprises a power supply line 13. The power supply line 13 comprises two impedances 14. Advantageously, the two identical impedances 14, in particular connected in series, extend between two ends 15, 16, respectively a first end 15 and a second end 16, of the power supply line 13.

[0060] According to the example presented in figure 2, the impedance 14 comprises, for example, a capacitor.

[0061] The first end 15 of the supply line 13 is connected to the first input terminal 8 and to the first output terminal 10. Furthermore, the second end 16 of the supply line 13 is connected to the second input terminal 9 and to the third output terminal 12.

[0062] The power supply module 5 further comprises an additional connection 17, in particular arranged between the two impedances 14, connected to the second output terminal 11. The electrical power converter 2 may also comprise a switching module 6. The switching module 6 comprises as many main switching arms as there are phases of the electrical load 3. According to the example presented in FIG. 2, the switching module 6 comprises three main switching arms 18, 19, 20, respectively a first main switching arm 18, a second main switching arm 19 and a third main switching arm 20.

[0063] The first main switching arm 18, respectively the second main switching arm 19 and / or the third main switching arm 20, comprises at least one first main switch 21, comprising a first end 23 and a second end 25, and at least one second main switch 22, comprising a first end 24 and a second end 26.

[0064] Advantageously, the first main switch 21 and the second main switch 22 are identical.

[0065] As shown in the exemplary embodiment of FIG. 2, the second end 25 of the first main switch 21 is connected to the first end 24 of the second main switch 22.

[0066] The first end 23 of the first main switch 21 is connected to a first input 27 of the switching module 6. Furthermore, the second end 26 of the second main switch 22 is connected to a second input 28 of the switching module 6. More particularly, the first input 27 of the switching module 6 is connected to the first output terminal 10 of the power supply module 5. In addition, the second input 28 of the switching module 6 is connected to the third output terminal 12 of the power supply module 5.

[0067] An intermediate connection 29, in particular a first intermediate connection 29, respectively a second intermediate connection 30 and a third intermediate connection 31, preferably arranged between the first main switch 21 and the second main switch 22, of the first main switching arm 18, respectively of the second main switching arm 19 and of the third main switching arm 20, is connected to a first output 32, respectively a second output 33 and a third output

[0068] 34, of the switching module 6.

[0069] The first output 32, respectively the second output 33 and the third output 34, of the switching module 6 is connected to a phase

[0070] 35, in particular a first phase 35, respectively a second phase 36 and a third phase 37, of the electric charge 3.

[0071] In a preferred embodiment, the first main switch 21 and the second main switch 22 are identical. Thus arranged, only one example of the first main switch 21 of the first main switching arm 18 is detailed.

[0072] The first main switch 21 comprises a transistor 38, in particular of the silicon (Si) type, for example of the MOSFET or IGBT type. The transistor 38 may comprise a diode 39, in particular an internal diode 39.

[0073] A drain D of the transistor 38 and a cathode of the diode 39 are connected to the first end 23 of the first main switch 21. Furthermore, a source S of the transistor 38 and an anode of the diode 39 are connected to the second end 25 of the first main switch 21. Finally, a gate G of the transistor 38 is connected to a control module 40 of the electrical power converter 2.

[0074] Alternatively, transistor 38 may be a silicon carbide transistor having an internal diode, the transistor being connected as previously described.

[0075] According to yet another variant, the transistor 38 may be a bipolar transistor to which a diode 39 is added, the diode 39 then being external. A collector of the transistor 38 is then connected to the first end 23 of the first main switch 21. In addition, an emitter of the transistor 38 is then connected to the second end 25 of the first main switch 21. Finally, a base of the transistor 38 is then connected to the control module 40 of the electrical power converter 2.

[0076] According to an exemplary embodiment, the control module 40 is produced from a processing unit.

[0077] The electrical power converter 2 may also comprise an auxiliary circuit 7. The auxiliary circuit 7 comprises as many control lines as there are main switching arms 18, 19, 20.

[0078] According to the exemplary embodiment presented in FIG. 2, the auxiliary circuit 7 comprises three control lines. Thus, more specifically, the auxiliary circuit 7 comprises a first control line 41, a second control line 42 and a third control line 43.

[0079] The first control line 41, respectively the second control line 42 and the third control line 43, comprises a first switching cell 44, respectively a second switching cell 45 and a third switching cell 46. Advantageously, the first switching cell 44, the second switching cell 45 and the third switching cell 46 are identical.

[0080] The first switching cell 44, respectively the second switching cell 45 and the third switching cell 46, comprises a first end 47, respectively a first end 48 and a first end 49, connected to a first input 50, respectively a second input 51 and a third input 52, of the auxiliary circuit 7 and a second end 53, respectively a second end 54 and a second end 55, connected to an output 56, respectively an output 57 and an output 58, of the auxiliary circuit 7. The first input 50, respectively the second input 51 and the third input 52, of the auxiliary circuit 7 is connected to the second output terminal 11 of the power supply module 5.

[0081] The output 56, respectively the output 57 and the output 58, of the auxiliary circuit 7 is connected to a second connection 59, respectively second connection 60 and a second connection 61, located between the first main switch 21 and the second main switch 22 of the first main switching arm 18, respectively of the second main switching arm 19 and of the third main switching arm 20.

[0082] Since the first switching cell 44, the second switching cell 45 and the third switching cell 46 are identical, only one exemplary embodiment of the first switching cell 44 and the first control line 41 are now detailed.

[0083] The first switching cell 44 of the first control line 41 comprises an auxiliary switch 62, in particular an auxiliary switch 62 made of silicon carbide (SiC), comprising a first transistor 63 and a second transistor 64, in particular a first transistor 63 and a second field effect transistor 64 made of silicon carbide (SiC), in particular an identical first transistor 63 and second transistor 64.

[0084] A drain DI of the first transistor 63 is connected to the first end 47 of the first switching cell 44 of the control line 41 and to the cathode of a diode 65, in particular as an internal diode of the first transistor 63.

[0085] Furthermore, a source SI of the first transistor 63 is connected to an anode of the diode 65 of the first transistor 63. Finally, the anode of the diode 65 of the first transistor 63 is connected to a source SI of the second transistor 64.

[0086] A drain DI of the second transistor 64 is connected to the second end 53 of the first switching cell 44 of the control line 41 and to the cathode of the diode 65, in particular as an internal diode of the second transistor 64.

[0087] A gate G1 of the first transistor 63, respectively of the second transistor 64, is connected to the control module 40.

[0088] Alternatively, the first switching cell 44 is likely to comprise several auxiliary switches 62 connected in series so as to reduce the voltage between the drain DI and the source SI of the first transistor 63, respectively of the second transistor 64, to increase the resistance of the first transistor 63, respectively of the second transistor 64, to high voltages.

[0089] According to another variant shown schematically in Figure 3, the auxiliary switch 62 comprises a first transistor 100 and a second field effect transistor 101 made of gallium nitride (GaN), advantageously identical.

[0090] The first gallium nitride field effect transistor 100 and the second gallium nitride field effect transistor 101 do not have an internal diode.

[0091] A drain D 100 of a first transistor 100 is connected to the first end 47 of the first switching cell 44 of the control line 41. Furthermore, a source S 100 of the first transistor 100 is connected to a drain D 101 of the second transistor 101. Finally, a source S 101 of the second transistor 101 is connected to the second end 53 of the first switching cell 44 of the control line 41.

[0092] A gate G 100 of the first transistor 100, respectively a gate G 101 of the second transistor 101, is connected to the control module 40. According to yet another embodiment shown schematically in FIG. 4, the auxiliary switch 62 may comprise a double-gate transistor 103, in particular a double-gate transistor 103 made of gallium nitride, controlled by a first trigger 104 and a second trigger 105.

[0093] The electrical power converter 2 further comprises a monitoring module 66, as shown schematically in FIG. 2. The monitoring module 66 is capable of being connected to a sensor 67 implemented in the immediate vicinity of the first transistor 63, respectively of the second transistor 64. The sensor 67 makes it possible to record a functional parameter of the first transistor 63, respectively of the second transistor 64, and to transmit it to the control module 40.

[0094] The monitoring module 66, for example produced from a processing unit, comprises determination means 68. The determination means 68 make it possible to determine a failure or a drift of the first transistor 63, respectively of the second transistor 64, of the auxiliary switch 62 from the functional parameter recorded by the sensor 67.

[0095] Advantageously, the determination means 68 are, for example, produced from a calculation unit implementing an ALGO detection algorithm.

[0096] When a failure or drift of the first transistor 63, respectively of the second transistor 64, of the auxiliary switch 62 is detected, the monitoring module 66 delivers an alert message to the control module 40 so that the first transistor 63, respectively the second transistor 64 of the auxiliary switch 62 is deactivated. The first transistor 63, respectively the second transistor 64, is in the blocked state.

[0097] The sensor 67 comprises, for example, a temperature sensor measuring a temperature of the first transistor 63, respectively of the second transistor 64. In such a case, the functional parameter of the first transistor 63, respectively of the second transistor 64, is the temperature of the first transistor 63, respectively of the second transistor 64.

[0098] The determination means 68 compare the temperature value recorded by the sensor 67 with a temperature threshold dependent on the technology of the first transistor 63, respectively of the second transistor 64, whether it is made of gallium nitride (GaN) or silicon carbide (SiC).

[0099] If the temperature detected by the sensor 67 is higher than the temperature threshold, the determination means 68 deliver the alert message.

[0100] Alternatively, the sensor 67 comprises a voltage sensor measuring a drain-source voltage of the first transistor 63, respectively of the second transistor 64. In such a case, the functional parameter of the first transistor 63, respectively of the second transistor 64, is the drain-source voltage of the first transistor 63, respectively of the second transistor 64.

[0101] The determination means 68 compare the value of the drain-source voltage detected by the sensor 67 to a voltage threshold depending on the technology of the first transistor 63, respectively of the second transistor 64, whether it is made of gallium nitride (GaN) or silicon carbide (SiC). If the drain-source voltage detected by the sensor 67 is greater than the voltage threshold, the determination means 68 deliver the alert message.

[0102] According to yet another variant, the sensor 67 measures a drain-source voltage, a current flowing through the drain and a temperature of the first transistor 63, respectively of the second transistor 64.

[0103] The determining means 68 determine the value of the drain-source resistance of the first transistor 63, respectively of the second transistor 64, and compare the determined value to a failure threshold.

[0104] If the value of the drain-source resistance determined for the first transistor 63, respectively of the second transistor 64, is greater than the failure threshold, the determination means 68 deliver the alert message.

[0105] The monitoring module 66 makes it possible to detect a failure and / or a drift of at least one of the auxiliary switches 62 so that, upon detection of a failure and / or a drift, all of the auxiliary switches are deactivated to prevent the propagation of a fault in the electrical power converter 2 likely to cause the failure of the electrical power converter 2, of the electrical load 3 and / or of the power source 4.

[0106] The control module 40 is further connected to a current sensor 69. The current sensor 69 detects a current flowing in the first phase 35, the second phase 36 and the third phase 37 of the electrical load 3.

[0107] Alternatively, the current sensor 69 is arranged outside the electrical load 3.

[0108] As long as no failure or drift of an auxiliary switch 62 has been detected, the control module 40 controls the first main switch 21 and the second main switch 22 of the corresponding switching arm, depending on the embodiment the first main switching arm 18, the second main switching arm 19 and / or the third main switching arm 20, and the corresponding switching cell, depending on the embodiment the first switching cell 44, the second switching cell 45 and / or the third switching cell 46, so that the electrical power converter 2 delivers three voltage levels on each phase of the electrical load 3 to supply and control the electrical load 3.

[0109] So :

[0110] - a first voltage level equal to +Ve is delivered by the first main switch 21 of each switching arm, depending on the embodiment the first main switching arm 18, the second main switching arm 19 and / or the third main switching arm 20,

[0111] - a second voltage level equal to -Ve is delivered by the second main switch 22 of each switching arm, according to the exemplary embodiment the first main switching arm 18, the second main switching arm 19, and / or the third main switching arm 20, and

[0112] - a third zero voltage level is delivered by the switching cell, depending on the embodiment the first switching cell 44, the second switching cell 45 and / or the third switching cell 46.

[0113] The first transistor 63 of the switching cell, according to the exemplary embodiment the first switching cell 44, the second switching cell 45, and / or the third switching cell 46, is blocked when the voltage between the first phase 35, the second phase 36, the third phase 37 of the electric load 3 and a ground is negative. Furthermore, the second transistor 64 of the switching cell, according to the exemplary embodiment the first switching cell 44, the second switching cell 45 and / or the third switching cell 46, is blocked when the voltage between the first phase 35, the second phase 36, the third phase 37 of the electric load 3 and a ground is positive so as to ensure the reversibility of the current in the phase.

[0114] When the auxiliary switch 62 is deactivated, the control module 40 deactivates the auxiliary circuit 7 and controls the first main switch 21, and the second main switch 22 of the corresponding switching arm, depending on the embodiment the first main switching arm 18, the second main switching arm 19 and / or the third main switching arm 20, so that the electrical power converter 2 delivers two voltage levels on each phase of the electrical load 3 to supply and control the electrical load 3.

[0115] So :

[0116] - A first voltage level equal to +Ve is delivered by the first main switch 21 of each switching arm, according to the exemplary embodiment the first main switching arm 18, the second main switching arm 19, and / or the third main switching arm 20, and

[0117] - a second voltage level equal to -Ve is delivered by the second main switch 22 of each switching arm, according to the exemplary embodiment the first main switching arm 18, the second main switching arm 19, and / or the third main switching arm 20.

[0118] The addition of the auxiliary circuit 7 to a two-level power converter makes it possible to produce the three-level power converter 2. The electrical power converter 2 according to the invention uses auxiliary switches 62 made of silicon carbide (SiC) or gallium nitride (GaN) so that the electrical power converter 2 is less bulky and generates less thermal losses than a three-level power converter known from the prior art.

[0119] Furthermore, when the monitoring module 66 detects the failure or drift of the auxiliary switch 62, the auxiliary circuit 7 is deactivated and the electrical power converter 2 delivers two voltage levels so that the electrical load 3 is supplied, thus ensuring continuity of service.

[0120] The control module 40 implements, for example, an algorithm of the pulse width modulation type, also known by the acronym PWM for “Pulse Width Modulation” in English.

[0121] Of course, the electric power converter 2 can comprise a number of phases other than three depending on the number of phases of the electric load 3.

[0122] Figure 5 schematically illustrates a second exemplary embodiment of the power supply module 5 according to the invention.

[0123] According to the second exemplary embodiment of the power supply module 5, the power supply module 5 differs from the exemplary embodiment illustrated in FIG. 2 in that

[0124] - the supply line 13 does not have an additional connection 17, and

[0125] - the power supply module 5 comprises an auxiliary switching arm 70, or first auxiliary switching arm 70, comprising a first end 71 connected to the first input terminal 8 of the power supply module 5 and a second end 72 connected to the second input terminal 9 of the power supply module 5.

[0126] The auxiliary switching arm 70 comprises a first secondary switch 73 comprising a first end 75 and a second end 77 and a second secondary switch 74 comprising a first end 76 and a second end 78. Preferably, the first secondary switch 73 and the second secondary switch 74 are identical,

[0127] The first end 75 of the first secondary switch 73 is connected to the first end 71 of the auxiliary switching arm 70. The second end 77 of the first secondary switch 73 is connected to the first end 76 of the second secondary switch 74. Furthermore, the second end 78 of the second secondary switch 74 is connected to the second end 72 of the auxiliary switching arm 70.

[0128] A third connection 79, or middle connection 79, is established between the first secondary switch 73 and the second secondary switch 74 and is connected to the second output terminal 11 of the power supply module 5.

[0129] Preferably, the first secondary switch 73 and the second secondary switch 74 are identical. Thus, only one example of embodiment of the first secondary switch 73 is detailed.

[0130] The first secondary switch 73 comprises a transistor 80, in particular of the silicon (Si) type, for example a field effect transistor of the MOSFET or IGBT type. Advantageously, the transistor 80 comprises a diode 81, in particular an internal diode 81.

[0131] A drain D2 of the transistor 80 and a cathode of the diode 81 are connected to the first end 75 of the first secondary switch 73. In addition, a source S2 of the transistor 80 and an anode of the diode 81 are connected to the second end 77 of the first secondary switch 73. Finally, a gate G2 of the transistor 80 is connected to the control module 40 of the electrical power converter 2. Alternatively, the transistor 80 comprises a bipolar transistor. In this case, a collector of the transistor is connected to the first end 75 of the first secondary switch 73. In addition, an emitter of the transistor is connected to the second end 77 of the first secondary switch 73. Finally, a base of the transistor is connected to the control module 40.

[0132] The 80 transistor is a proven technology, particularly for aeronautical applications.

[0133] The electrical power converter 2 comprising the power supply module 5 according to this embodiment delivers two voltage levels:

[0134] - a first voltage level equal to +Ve is delivered by the first main switch 21 of each switching arm, according to the exemplary embodiment the first main switching arm 18, the second main switching arm 19 and / or the third main switching arm 20, and

[0135] - a second voltage level equal to -Ve is delivered by the second main switch 22 of each switching arm, depending on the embodiment the first main switching arm 18, the second main switching arm 19 and / or the third main switching arm 20.

[0136] Auxiliary circuit 7 is deactivated.

[0137] When detecting the failure or drift of the first main switch 21 and / or the second main switch 22 of one of the main switching arms, depending on the embodiment the first main switching arm 18, the second main switching arm 19, and / or the third main switching arm 20, the first main switch 21 and / or the second main switch 22 which is faulty or drifting is deactivated by the control module 40.As long as no failure or drift of the auxiliary switch 62 has been detected, the control module 40 controls the switching cell 62 of the first control line 41, respectively of the second control line 42 and / or of the third control line 43, connected to the first main switching arm 18, respectively to the second main switching arm 19 and / or to the third main switching arm 20, comprising the first main switch 21, respectively the second main switch 22 and / or the third main switch 23, faulty or drifting and the first secondary switch 73 and / or the second secondary switch 74, so as to supply the phase connected to the faulty or drifting main switch of the electrical load 3 by two voltage levels.

[0138] The first secondary switch 73, respectively the second secondary switch 74, controlled by the control module 40 replaces the faulty or bypassed switch. The first secondary switch 73, respectively the second secondary switch 74, constitutes a replacement switch which is controlled by the control module 40 in the same way as the faulty or bypassed main switch. The switching cell 62 is controlled by the control module 40 so as to allow the voltage and current delivered by the first secondary switch 73, respectively the second secondary switch 74, to pass as a replacement switch.

[0139] In particular, when detecting a failure of the first main switch 21 of the first main switching arm 18 and / or of the second main switching arm 19 and / or of the second main switching arm 20, the control module 40 controls the first secondary switch 73 and the switching cell 62 of the first control line 41 and / or of the second control line 42 and / or of the third control line 43 connected respectively to the first main switching arm 18, to the second main switching arm 19 or to the third main switching arm 20 comprising the faulty or drifting first main switch 21.

[0140] When detecting a failure of the second main switch 22 of the first main switching arm 18 and / or of the second main switching arm 19 and / or of the second main switching arm 20, the control module 40 controls the second secondary switch 74 and the switching cell 62 of the first control line 41 and / or of the second control line 42 and / or of the third control line 43 connected to the first main switching arm 18 to the second main switching arm 19 or to the third main switching arm 20 comprising the faulty or drifting second main switch 22.

[0141] The auxiliary circuit 7 and the auxiliary switching arm 70 make it possible to compensate for a failure of the first main switch 21 and / or the second main switch 22 of the first main switching arm 18 and / or the second main switching arm 19 and / or the second main switching arm 20 making it possible to ensure continuity of service of the electrical power converter 2.

[0142] If the first switching cell 44 and / or the second switching cell 45 and / or the third switching cell 46 of the auxiliary circuit 7 is / are faulty or drifting, the control module 40 deactivates the electrical power converter 2, the electrical load 3 no longer being supplied.

[0143] We now refer to Figure 6 which schematically represents a third embodiment of the electrical power converter 2 according to the invention.

[0144] According to the third embodiment, the electrical power converter 2 comprises an auxiliary circuit 7, preferably identical to the auxiliary circuit 7 described in relation to the first embodiment of the figure, connected to a power supply module 5. According to the third embodiment, the electrical power converter 2, the power supply module 5 differs from the exemplary embodiment illustrated in figure 5 in that

[0145] - the supply line 13 does not have an additional connection 17,

[0146] - the power supply module 5 comprises o a first auxiliary switching arm 70 connected to the power supply line 13 and to the second output terminal 11, similar to the auxiliary switching arm 70 as detailed in FIG. 5, and o furthermore, at least one second auxiliary switching arm 82, in particular a second auxiliary switching arm 82 and a third auxiliary switching arm 83, in particular identical to the first auxiliary switching arm 70, and more specifically identical to the auxiliary switching arm 70 detailed in FIG. 5.

[0147] The power supply module 5 of the third embodiment, the electric power converter 2 comprises as many auxiliary switching arms as there are control lines of the auxiliary circuit 7.

[0148] The power supply module 5 of the third embodiment, the electric power converter 2 comprises a first output terminal 10, a second output terminal 11 and a third output terminal 12.

[0149] The second auxiliary switching arm 82 comprises

[0150] - a first end 84, connected to the first input terminal 8 of the power supply module 5,

[0151] - a second end 85, connected to the second input terminal 9 of the power supply module 5, and

[0152] - a fourth connection 86, or middle connection 86, connected to a fourth output terminal 87 of the power supply module 5. The third auxiliary switching arm 83 comprises

[0153] - a first end 88, connected to the first input terminal 8 of the power supply module 5,

[0154] - a second end 89, connected to the second input terminal 9 of the power supply module 5, and

[0155] - a fifth connection 90, or middle connection 90, connected to a fifth output terminal 91 of the power supply module 5.

[0156] The second output terminal 11 and the fourth output terminal 87 and the fifth output terminal 90 of the power supply module 5 are connected to a different input of the auxiliary circuit 7.

[0157] When the electrical load 3 comprises a number of phases other than three, the power supply module 5 comprises as many auxiliary switching arms as there are control lines of the auxiliary circuit 7, each auxiliary switching arm being connected to a different control line of the auxiliary circuit 7.

[0158] For example, the second output terminal 11 is connected to a first input 50 of the auxiliary circuit 7, the fourth output terminal 87 is connected to a second input 51 of the auxiliary circuit 7 and the fifth output terminal 90 is connected to the third input 52 of the auxiliary circuit 7.

[0159] The first auxiliary switching arm 70 and the first control line 41 of the auxiliary circuit 7 make it possible to compensate for a failure of the first main switch 21 and / or the second main switch 22 of the first main switching arm 18.

[0160] The second auxiliary switching arm 82 and the second control line 42 of the auxiliary circuit 7 make it possible to compensate for a failure of the first main switch 21 and / or the second main switch 22 of the second main switching arm 19. Tl

[0161] The third auxiliary switching arm 83 and the third control line 43 of the auxiliary circuit 7 make it possible to compensate for a failure of the first main switch 21 and / or the second main switch 22 of the third main switching arm 20.

[0162] The first auxiliary switching arm 70, the second auxiliary switching arm 82 and the third auxiliary switching arm 83 and the first control line 41, the second control line 42 and the third control line 43 operate as previously described to overcome the failure of the first main switch 21 and / or the second main switch 22 failing or drifting.

[0163] In the embodiment of Figure 6, the power supply module 5 and the auxiliary circuit 7 make it possible to compensate for the failure or drift of the first main switch 21 and / or the second main switch 22 by main switching arm as long as the auxiliary circuit 7 is not deactivated.

[0164] Unlike the embodiment illustrated in Figure 5, which makes it possible to overcome a single failure or drift of the first main switch 21 and / or the second main switch 22 of the assembly of the first main switching arm 18, the second main switching arm 19 and the third main switching arm 20, the embodiment illustrated in Figure 6 makes it possible to overcome three failures or drifts, each failure or drift appearing on the first main switch 20 and / or the second main switch 21 of the first main switching arm 18, the second main switching arm 19 and / or the third main switching arm 20, making it possible to improve the continuity of service of the electrical power converter 2.

[0165] We now refer to Figure 7 which schematically represents a third embodiment of the electrical power converter 2 according to the invention. According to the third embodiment of the electrical power converter 2, the auxiliary circuit 7 is connected to a fourth embodiment of the power supply module 5 comprising the power supply line 13 and the auxiliary switching arm 70 as shown in Figure 5.

[0166] Furthermore, according to the third embodiment of the electrical power converter 2, the power supply line 13 further comprises an additional connection 17.

[0167] In addition, the power supply module 5 further comprises a selection switch 92. The selection switch 92 may comprise a control input 93, in particular connected to the control module 40, a first power input 94, a second power input 95 and a power output 96, in particular connected to the second output terminal 11 of the power supply module 5.

[0168] According to the example presented, the first power input 94 is connected to the third connection 79 of the auxiliary switching arm 70 and the second power input 95 is connected to the additional connection 17 of the power supply line 13.

[0169] As long as no failure or drift of one of the auxiliary switches 62 of the auxiliary circuit 7 is detected, the control module 40 controls the selection switch 92 so that the second power input 95 is connected to the power output 96.

[0170] The electrical power converter 2 delivers three voltage levels on the first phase 35, the second phase 36 and the third phase 37 of the electrical load 3 as described in relation to FIG. 2.

[0171] If one of the auxiliary switches 62 of the auxiliary circuit 7 is faulty or drifts, the auxiliary circuit 7 is deactivated and the electrical power converter 2 delivers two voltage levels on the first phase 35, the second phase 36 and the third phase 37 of the electrical load 3 as described in relation to FIG. 2.

[0172] As long as no failure or drift of one of the auxiliary switches 62 of the auxiliary circuit 7 is detected, and if the first main switch 21 and / or the second main switch 22 of the first main switching arm 18, respectively of the second main switching arm 19 and / or of the third main switching arm 20, is faulty, the control module 40 controls the selection switch 92 so that the first power input 94 is connected to the power output 96.

[0173] As a result, the control module 40 controls the auxiliary circuit 7 and the auxiliary switching arm 70 so that the faulty or drifting main switch is substituted by the first secondary switch 73 and / or the second secondary switch 74 of the auxiliary switching arm 70 as described in relation to FIG. 5.

[0174] The third embodiment of the electrical power converter 2 makes it possible to obtain a power converter 2 delivering three voltage levels when no failure or drift of one of the auxiliary switches 62 and of the first main switch 21 and / or of the second main switch 22 is detected, the electrical power converter 2 generating fewer losses, and being able to be less bulky, than a three-level converter known from the state of the art.

[0175] If one of the auxiliary switches 62 is faulty or drifts, the electrical power converter 2 delivers two voltage levels to ensure continuity of supply to the electrical load 3.

[0176] Finally, if no failure or drift of one of the auxiliary switches 62 is detected and the first main switch 21 and / or the second main switch 22 is faulty or drifting, the first secondary switch 73 and / or the second secondary switch 74 replaces the first main switch 21 and / or the second main switch 22 which is faulty or drifting, making it possible to ensure the continuity of supply of the electrical load 3 during the failure or drift of the first main switch 21 and / or the second main switch 22.

[0177] The reliability of the electrical power converter 2 allowing the continuity of supply of the electrical load 3 is improved.

[0178] According to another embodiment, the power supply module 5 comprises three auxiliary switching arms as shown in relation to FIG. 6, in particular the first auxiliary switching arm 70, the second auxiliary switching arm 82 and / or the third auxiliary switching arm 83.

[0179] According to such an arrangement,

[0180] - the third connection 79 of the first auxiliary switching arm 70, the fourth connection 86 of the second auxiliary switching arm 82 and the fifth connection 90 of the third auxiliary switching arm 83, are connected to a first power input of a different selection switch,

[0181] - a second power input of each different selection switch being connected to the first end 15 or to additional connection 17 of the power supply line 13, and

[0182] - the power output of each selection switch being connected to an input of the auxiliary circuit 7.

[0183] In this other embodiment, if no failure or drift of one of the auxiliary switches 62 is detected and the first main switch 21 and / or the second main switch 22 of the first main switching arm 18, respectively of the second main switching arm 19 and / or of the third main switching arm 20, are faulty or drifting, the control module 40 controls one or more of the selection switches connected to the main switching arms comprising the first main switch 21 and / or the second main switch 22 faulty or drifting so that the power output of the selection switches is connected to the first power input of the selection switches.

[0184] As a result, the control module 40 controls the auxiliary switching arms 70 so that the first main switch 21 and / or the second main switch 22 which is faulty or drifting are replaced by the first secondary switch 73 and / or the second secondary switch 74.

[0185] Such an embodiment makes it possible to further improve the reliability of the electrical power converter 2 by compensating for the failure or drift of the first main switch 21 and / or the second main switch 22 by main switching arm as long as no auxiliary switch 62 is faulty.

[0186] Figure 8 schematically illustrates another embodiment of the first main switching arm 18, the second main switching arm 19 and / or the third main switching arm 20.

[0187] Such an embodiment of the first main switching arm 18, the second main switching arm 19 and / or the third main switching arm 20 can be combined with all of the embodiments of the electrical power converter 2 described above. This makes it possible to obtain an electrical power converter 2 that is even more compact and / or generates even fewer thermal losses.

[0188] The first main switch 21, respectively the second main switch 22, comprises a transistor 200, in particular a gallium nitride transistor 200, in particular a gallium nitride field effect transistor 200.

[0189] Transistor 200 includes a drain D200, a source S200, and a gate G200. However, transistor 200 does not include an internal diode.

[0190] The drain D200 of the transistor 200 of the first main switch 21 is connected to the first end 23 of the first main switch 21, the source S200 of the transistor 200 is connected to the second end 25 of the first main switch 21 and the gate G200 is connected to the control module 40.

[0191] The drain D200 of the transistor 200 of the second main switch 22 is connected to the first end 24 of the second main switch 22, the source S200 of the transistor 200 is connected to the second end 26 of the second main switch 22 and the gate G200 is connected to the control module 40.

[0192] In the detailed presentation of the invention given above, the terms used should not be interpreted as limiting the invention to the embodiments set forth in the description just given, but should be interpreted to include all equivalents the prediction of which is within the reach of those skilled in the art by applying their general knowledge to the implementation of the teaching just disclosed to them.

[0193] Obviously, the invention is not limited to the embodiments described above and provided solely as examples. It encompasses various modifications, alternative forms and other variants that may be envisaged by those skilled in the art within the framework of the present invention and in particular all combinations of the different operating modes described above, which may be taken separately or in association.

Claims

CLAIMS 1. Electrical power converter (2) for supplying an electrical load (3), in particular of an aircraft (1), comprising - a power supply module (5), intended to be connected to a power supply source (4), in particular a continuous power supply source (4); - at least one main switching arm (18, 19, 20) comprising a first main switch (21) and a second main switch (22), in particular a first main switch (21) and a second main switch (22) which are identical, respectively comprising a first end (23, 24) and a second end (25, 26), the first end (23) of the first main switch (21) and the second end (26) of the second main switch (22) being connected to the power supply module (5) and the second end (25) of the first main switch (21) being connected to the first end (24) of the second main switch (22); - at least one intermediate connection (29, 30, 31), arranged between the first main switch (21) and the second main switch (22) and intended to be connected to a phase (35, 36, 37) of the electrical load (3); - an auxiliary circuit (7) comprising as many control lines (41, 42, 43) as main switching arms (18, 19, 20), at least one control line (41, 42, 43) comprising at least one switching cell (44, 45, 46) comprising o a first end (47, 48, 49) connected to the power supply module (5) and o a second end (53, 54, 55) connected to the intermediate connection (29, 30, 31), characterized in that the switching cell (44, 45, 46) comprises at least one auxiliary switch (62), in particular an auxiliary switch (62) made of silicon carbide or gallium nitride.

2. Electrical power converter (2) according to claim 1, wherein the electrical power converter (2) comprises a monitoring module (66) configured to detect a failure or drift of the auxiliary switch (62) from functional parameters of the auxiliary switch (62) and to deactivate the auxiliary switch (62) upon detection of a failure or drift of the auxiliary switch (62).

3. Electrical power converter (2) according to claim 1 or 2, wherein the power supply module (5) comprises a power supply line (13) comprising a first end (15) and a second end (16) intended to be connected to the power supply source (4) and wherein the power supply line (13) comprises two impedances (14), in particular two identical impedances (14), in particular capable of being connected in series.

4. Electrical power converter (2) according to claim 3, in which the power supply module (5) comprises an additional connection (17) arranged between the two impedances (14) and intended to be connected to the first end (47, 48, 49) of the switching cell (44, 45, 46).

5. Electrical power converter (2) according to any one of the preceding claims, wherein the electrical power converter (2) comprises at least one auxiliary switching arm (70, 82, 83) comprising a first secondary switch (73) and a second secondary switch (74), in particular a first secondary switch (73) and a second secondary switch (74) which are identical, respectively comprising a first end (75, 76) and a second end (77, 78), the second end (77) of the first secondary switch (73) being connected to the first end (76) of the second secondary switch (74).

6. Electrical power converter (2) according to claim 5, wherein a middle connection (79, 86, 90) is arranged between the first secondary switch (73) and the second secondary switch (74) and is connected to the first end (47, 48, 49) of the switching cell (44, 45, 46) of the control line (41, 42, 43).

7. Electrical power converter (2) according to any one of claims 1 to 4 taken in combination with claim 5 or 6, wherein the first end of the first main switch (21) and / or the first secondary switch (73), and the second end of the second main switch (22) and / or the second secondary switch (74) are respectively connected to a different end of the power supply line (13).

8. Electrical power converter (2) according to any one of the preceding claims, wherein the power supply module (5) further comprises a selection switch (92) comprising a control input (93), a first power input (94), a second power input (95) and a power output (96), and configured to connect the power output (96) to one of the power inputs according to a signal received on the control input (93).

9. Electrical power converter (2) according to claim 8 taken in combination with claim 6, wherein - the first power input (94) is connected to the middle connection (79, 86, 90), - the second power input (95) is connected to the additional connection (17) and - the power output (96) is connected to the first end (47, 48, 49) of the switching cell (44, 45, 46) of the control line (41, 42, 43).

10. Electric power converter (2) according to claim 3, wherein the first main switch (21), respectively the second main switch (22), is made of silicon carbide or gallium nitride (200). 1 1. Electric power converter (2) according to claim 3, wherein the first secondary switch (73), respectively the second secondary switch (74) is made of silicon.

12. Electrical power converter (2) according to any one of the preceding claims, wherein the first main switch (21), respectively the second main switch (22), comprises a transistor (103), in particular a double gate transistor (103), in particular a double gate transistor (103) made of gallium nitride.

13. Electrical power converter (2) according to one of the preceding claims, in which the auxiliary switch (62) comprises at least a first transistor (100) and a second transistor (101), in particular a first transistor (100) and a second transistor (101) made of gallium nitride, connected in series so that - a source (S 100) of the first transistor (100) is connected to a drain (D 101) of the second transistor (101), - a drain (D 100) of the first transistor (100) and a source (S 101) of the second transistor (101) are connected to a different end of the switching cell (44, 45, 46).

14. Aircraft (1) comprising an electric power converter (2) according to one of the preceding claims.

15. Method for supplying electricity to an electrical load (3), in particular for an aircraft (1), connected to an electrical power converter (2) according to any one of claims 1 to 7: comprising the control of the first main switch (21) and the second main switch (22) so as to supply a phase of the electrical load (3), characterized in that the method of supplying electricity to an electrical load (3) further comprises at least one step of detecting a failure or a drift of the auxiliary switch (62) from functional parameters of the auxiliary switch (62), and a step of deactivating the auxiliary switch (62) upon detection of a failure or a drift of the auxiliary switch (62).

16. Method for supplying electrical power to an electrical load (3) according to claim 15, further comprising: a step of controlling the switching cell (44, 45, 46) so as to supply the phase with three voltage levels as long as no failure or drift of the auxiliary switch (62) has been detected, and a step of deactivating the auxiliary switch (62), controlling the first main switch (21) and the second main switch (22) so as to supply the phase with two voltage levels.

17. Method for supplying electricity to an electrical load (3) according to claim 16, further comprising: upon detection of the failure or drift of the first main switch (21) and of the second main switch (22), deactivation of the faulty or drifting switch, and as long as no failure or drift of the auxiliary switch (62) has been detected, control of the switching cell (44, 45, 46) and of the first secondary switch (73) and / or of the second secondary switch (74) so ​​as to supply the phase of the load by two voltage levels, the secondary controlled switch replacing the faulty switch.

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