Electrical power supply system for an aircraft actuator

Abstract

Aircraft actuator power supply architecture, comprising a single-phase on-board electrical network connected by a power supply line to an electric motor of at least one actuator, the power supply line successively comprising an upstream conversion device for converting the voltage of the on-board electrical network into a voltage adapted to the downstream power supply line, at least one supercapacitor associated with an electronic circuit for managing the operation of the supercapacitor, and a downstream conversion device intended to be connected to the motor;the downstream conversion device being reversible to provide voltage conversion both when the motor is in motor operating mode and when the motor is in generator operating mode, the downstream conversion device being arranged to selectively have a voltage step-down function and a voltage step-up function regardless of the operating mode of the motor such that the supercapacitor can supply the motor in motor operating mode and be recharged by the motor in generator operating mode. FIGURE OF THE ABSTRACT: [Fig. 1];

Description

Description Title of the invention: Power supply system for an AC- aircraft tioner

[0001] — The present invention relates to the field of aeronautics and more particularly electrical actuation of aircraft equipment, including mobile equipment such as: a landing gear, a landing gear wheel brake, a thrust reverser, a movable flight surface for primary or secondary control such as an aileron or a shutter.…

[0002] = BACKGROUND OF THE INVENTION

[0003] — Aircraft often include at least a single-phase electrical network and a three-phase electrical network.

[0004] — The single-phase electrical network is considered insufficiently powerful for power the aircraft's mobile equipment, such as flight surfaces, the in- thrusters, brakes, and landing gear. The three-phase electrical network is therefore used for actuation of mobile equipment by providing the necessary power necessary for the electromechanical actuators used to move the equipment mobiles between their different service positions.

[0005] — Thus, the architecture of the power supply system for these actuators includes gen- Approximately a power line connecting the actuator motors to the network Three-phase electrical supply. The supply line most often includes:

[0006] - an input filter to eliminate electrical disturbances (overvoltages, over- intensities) transmitted by the three-phase electrical network and to which are sensitive components of the power supply system; a diode bridge rectifier, transformer / rectifier, or a power factor correction (PFC); a current limiter; an LC-type damped filter to limit inrush current at startup and avoid a collapse in input voltage; a decoupling capability; a three-phase inverter; a dissipation or braking resistor; an inverter output filter.

[0007] It appears that power requirements occur in the form of peaks such as visible in [fig.1] which represents the power consumed as a function of time for a fin actuator. The power required at peak power is supplied by the three-phase network so that all the system components The power supply must be sized to absorb these power peaks. This results in a relatively significant weight, which is very detrimental to aeronautical applications. SUBJECT OF THE INVENTION The invention aims in particular to enable the power supply of aircraft actuators while limiting the weight carried. Summary of the invention For this purpose, an architecture according to claim 1 is provided according to the invention. Thus, the supercapacitor provides the majority of the power required by the motor during peak power demands, and the network serves only to supplement this power when necessary, maintain the supercapacitor's charge, or supply the motor with power outside of peak power periods. Furthermore, the supercapacitor is recharged by the motor in generator mode when aerodynamic forces act on the moving equipment associated with the actuator. The downstream conversion device regulates the voltage and current across the motor terminals when it operates in motor mode and across the supercapacitor terminals when the motor operates in generator mode. Therefore, it is not necessary to size the entire architecture based on power peaks, but only the portion downstream of the supercapacitor.This results in a weight reduction and, consequently, a decrease in fuel consumption for aircraft propulsion. The invention also relates to an aircraft comprising a three-phase on-board electrical network and a single-phase on-board electrical network, the latter being part of an actuator power supply architecture such as the one mentioned above. Other features and advantages of the invention will become apparent from the following description of a particular, non-limiting embodiment of the invention. Brief description of the drawings Reference will be made to the attached drawings, among which: [fig.1] the [fig.1] represents the power consumed as a function of time for a fin actuator; [fig.2] the [fig.2] represents the power to be supplied and the power delivered as a function of time for a thrust reverser actuator; [fig.3] The [fig.3] is a schematic view of the actuation system of an aircraft equipment, according to a first embodiment of the invention, with a single-phase DC voltage on-board network and an internal high-voltage bus; [fig.4] [fig.4] is a schematic view of the downstream conversion device of the actuation system according to the first embodiment of the invention; [fig.5] The [fig.5] is a schematic view of the actuation system according to a second embodiment of the invention, the downstream conversion device having a different structure from that of [fig.4]; [fig.6] Fig.6 is a schematic view of the actuation system according to a third embodiment of the invention, with a single-phase DC voltage on-board network, the downstream conversion device of the second embodiment and an internal low-voltage bus: [fig.7] the [fig.7] is a schematic view of the actuation system according to a fourth embodiment identical to the third embodiment except that the upstream conversion device is reversible; [fig.8] The [fig.8] is a schematic view of the actuation system of an aircraft equipment, according to a fifth embodiment of the invention, for a single-phase AC voltage on-board network; [Fig. 9] Figure 9 is a schematic view of an aircraft according to the invention. DETAILED DESCRIPTION OF THE INVENTION With reference to [Fig. 9], the invention is described herein in application to an aircraft A comprising two onboard electrical systems, namely a three-phase electrical system E1 and a single-phase electrical system E2. The three-phase electrical system E1 is, for example, subjected to an alternating voltage of 115V or 230V, and the single-phase electrical system E2 is, for example, subjected to a direct voltage of 28V or 115V, depending on the embodiments envisaged. The aircraft A comprises movable equipment, including movable flight surfaces V (primary control) and thrust reversers T. The movable equipment is moved between its various operating positions by electromechanical actuators 1. Aircraft A is equipped with an electromechanical actuator power supply architecture, of which the single-phase electrical network E2 is a part. The power supply architecture includes at least one power line, generally designated as 100, connecting the single-phase electrical network E2 to an electric motor 2 of each of the actuators 1. The circuit of the motor 2 of each actuator 1 is arranged to have a motor operating mode in which the motor 1 transforms the electrical energy supplied to it into mechanical energy moving the mobile equipment, and a generator operating mode in which the motor 1 transforms the mechanical energy transmitted to it by the mobile equipment into electrical energy. For the sake of simplicity, the invention is described here in application to the power supply of a single motor; it is understood, however, that the power supply architecture can be adapted to power several motors. This is the case, for example, when the mobile equipment is moved by several actuators, each comprising one motor, or by several motors of a single actuator. The power supply architecture preferably includes as many power supply lines as there are sets of actuators acting on the same equipment. The supply line 100 includes successively an upstream conversion device 110, an energy storage device 120 connected by an internal bus to the upstream conversion device 110, and a downstream conversion device 130 connected by an internal bus to the energy storage device 120 and to the motor. The energy storage device 120 includes supercapacitors 121 and an electronic circuit 122 for managing the operation of the supercapacitors 121. The electronic circuit 122 is known in itself and monitors the charging and discharging of the supercapacitors 121, ensuring the balancing of charge levels between them. A conversion device is defined as any electrical / electronic circuit that transforms an input voltage into one or more output voltages. More specifically, the upstream conversion device 110 is configured to convert the single-phase mains voltage E2 into a first internal bus voltage to power the supercapacitors 121 and the upstream conversion device during off-peak power periods. This first internal bus voltage is single-phase and DC. The upstream conversion device 110 is sized to compensate for energy losses in the supercapacitors 121 due to leakage currents and to provide supplemental power to the downstream conversion device 130 during peak power periods. Furthermore, the downstream conversion device 130 is reversible to ensure voltage conversion both when motor 2 is in motor operating mode and when motor 2 is in generator operating mode. The downstream conversion device 130 is arranged to selectively have a voltage step-down function and a voltage step-up function regardless of the operating mode of motor 2, such that the supercapacitors 121 can supply motor 2 in motor operating mode and be recharged by motor 2 in generator operating mode.The downstream conversion device 130 is thus arranged to, on the one hand, convert the first internal bus voltage into a three-phase AC supply voltage for the windings of motor 2 to drive the motor in motor mode and, on the other hand, convert a three-phase AC voltage supplied by the motor in generator operating mode into a voltage suitable for recharging the supercapacitors 121. Indeed, the downstream conversion device 130 must allow the input and output voltage to be regulated regardless of the operating mode considered: this is particularly interesting in generator operating mode because it is then possible to lower the voltage to prevent an overvoltage beyond the maximum voltage acceptable by the supercapacitors 121 or, on the contrary, to increase the voltage to accelerate the charging of the supercapacitors 121 (while remaining below the maximum voltage acceptable by the . supercapacitors 121). In the first embodiment shown in [fig.3], the single-phase electrical network F2 provides a low DC voltage of 28V and the first internal bus voltage is a high DC voltage of 270V. The upstream conversion device 110 is here a DC / DC step-up voltage converter which is sized to convert the single-phase DC voltage of 28V into the single-phase DC voltage of 270V and which is connected to the energy storage device 120 by an internal bus at the first internal bus voltage. The downstream conversion device 130 comprises a Buck-boost topology inverter, more specifically a Y-Buck-boost inverter, as shown in [Fig. 4]. For each phase of the motor 2, this inverter comprises a first bridge of transistors T1 and T2 (Buck bridge) with a midpoint connected via an inductor to the midpoint of a second bridge of transistors T3 and T4 (Boost bridge), in parallel with which a capacitor is mounted. The inverter is controlled in a manner known per se and, for example, by implementing the control method described in document FR-A-3066660. In the second embodiment, and with reference to [fig.5], the downstream conversion device 130 comprises a DC / DC converter 131 and a step-down inverter 132, both replacing the Buck-Boost type inverter of [fig.4]. The DC / DC converter 131 is configured as a voltage step-up, reversible, and isolated converter, and is connected to the energy storage device 121 via an internal bus at the first internal bus voltage, which is 270V DC. The DC / DC converter regulates the voltage across the supercapacitors 121. The DC / DC converter 131 is of the "Dual Active Bridge" type. The step-down inverter 132 is reversible and is connected to motor 2. The DC / DC converter 131 and the step-down inverter 132 are connected to each other by an internal bus isolated to the first internal bus voltage, here 270V DC. The upstream conversion device 110 is, as before, a DC / DC step-up voltage converter which is sized to convert the single-phase DC voltage of 28V into the single-phase DC voltage of 270V and which is connected to the energy storage device 120 by an internal bus at the first internal bus voltage. Note that: In generator mode, the voltage applied to the supercapacitors 121 is regulated to avoid exceeding the maximum voltages and currents supported by supercapacitors 121; In motor mode, the permissible voltage variation on the internal bus is greatly expanded (within acceptable current limits) for the same amplitude of the phase voltages of motor 2 in order to reach the domain of desired engine speed. The third embodiment of [Fig. 6] is identical to the second embodiment except that the energy storage device 120 is connected to the upstream conversion device 110 by an internal bus at a relatively low initial voltage, here 28V DC, and to the downstream conversion device 130 by an internal bus at the initial voltage, also 28V DC. The conversion device 110 and the DC / DC converter 131 are adapted to these voltage values. Thus, the DC / DC converter 131 is configured as a voltage step-up, reversible, and isolated converter, and is connected to the energy storage device 121 via an internal bus at the first internal bus voltage, which is 270V DC. The DC / DC converter 131 is configured to significantly increase the voltage to power the inverter 132 in motor mode and to regulate the voltage across the supercapacitors 121 in generator mode. The DC / DC converter 131 is of the "Dual Active Bridge" type. The galvanic isolation of the DC / DC converter 131 provides a barrier between the supercapacitors 121 and the motor 2 to prevent uncontrolled power supply to the motor 2. It also allows a very low DC voltage to be generated on the inverter 132 to verify its operability before use ("power built in test / in flight test"). According to the fourth embodiment illustrated in [fig.7], the upstream conversion device 110 is connected to the energy storage device 120 by an internal bus at a first relatively low voltage, here 28V DC, and is arranged to be reversible and to have a voltage step-down function and a voltage step-up function to allow energy distribution from the supercapacitors 121 to the single-phase electrical network E2. As before, the downstream conversion device 130 includes a DC / DC converter 131 and a step-down voltage inverter 132. The DC / DC converter 131 is configured as a reversible, isolated step-up converter and is connected to the energy storage device 121 via an internal bus at the first internal bus voltage, which is 28V DC. The reversible step-down inverter 132 is connected, on one side, to the motor 2 and, on the other side, to the DC / DC converter 131 via an isolated internal bus at a second, relatively high internal bus voltage, which is 270V DC. It is then possible to store energy in storage means distributed throughout the aircraft and connected to the single-phase electrical network E2. According to the fifth embodiment of [Fig. 8], the single-phase electrical network E2 delivers an alternating voltage of 115V and the upstream conversion device 110° comprises a passive half-wave rectifier or a power factor correction rectifier. The remainder of the supply line 100 is identical to that of [Fig. 3]. In all embodiments, the supercapacitors 121, the supercapacitor operation management circuit 122, the upstream conversion device 110, 110” and at least part of the downstream conversion device 130 are part of the same electronic device incorporating at least one processor. For the actuation of the thrust reverser T, it is noted in [fig.2] that the actuation sequence includes: a first driving phase in which the supercapacitors 121 must to provide a relatively short power peak to initiate the movement of the thrust reverser T towards its exit position, a second generating phase, in which the aerodynamic forces- drag the thrust reverser T to its extended position and the engine 2 acting as a generator, it recharges the supercapacitors 121, a third driving phase in which the supercapacitors 121 must provide a relatively long power peak to bring the inverter back push T from its exit position to its retracted position. Preferably, in this application, the supercapacitors 121 are sized so that they are not fully charged during the aircraft's flight time, with complete recharging of the supercapacitors occurring during the second power phase. This is valid for any application implementing an actuation sequence beginning with a relatively low-power generator or drive phase followed by a generator phase. When there is a risk of supercapacitor oversaturation during the generator phase, it is preferable to provide an energy dissipation resistor connected to the downstream conversion device to dissipate the energy produced when the motor is in generator operating mode and the supercapacitors are saturated. Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims. In particular, the power supply architecture may have a different structure than that described. For example, the downstream conversion device may include a converter with a Boost, Buck-boost, Cuk… topology We can plan to size the supercapacitors to ensure the supplying peak power, the onboard electrical network only serves to compensate for leakage current losses. It is possible to pre-charge the supercapacitors before the flight, or to charge them only during the flight, depending on the duration of the flight. The invention is applicable to all types of equipment for the electrical actuation of aircraft equipment, and in particular mobile equipment such as: a landing gear, a landing gear wheel brake, a thrust reverser, a movable flight surface for primary or secondary control such as an aileron or a flap…

Claims

Demands

1. Aircraft actuator power supply architecture, comprising a single-phase onboard electrical system, connected by a power line to an electric motor with at least one actuator, the power supply line comprising successively an upstream conversion device for convert the voltage of the onboard electrical network to a suitable voltage to the downstream power line, at least one associated supercapacitor to an electronic circuit for managing the operation of the supercon- densifier, and a downstream conversion device intended to be connected to the engine; the downstream conversion device being reversible to ensure a voltage conversion at a time when the motor is in mode engine operation and when the engine is in operating mode generator operation, the downstream conversion device being arranged to selectively have a voltage-stepping function and a voltage boost function regardless of operating mode of the motor in such a way that the supercapacitor can power the engine in engine operating mode and be recharged by the engine in generator operating mode.

2. Architecture according to claim 1, wherein the device of downstream conversion includes a Buck-Boost topology inverter.

3. Architecture according to claim 1, wherein the device of downstream conversion includes a step-up DC / DC converter reversible and isolated, connected to a supercapacitor and a step-down inverter reversible voltage connected in series to the DC / DC converter elevator and engine.

4. Architecture according to claim 3, wherein the converter continuous / continuous boost converter is of the "Dual Active Bridge" type.

5. Architecture according to claim 3 or 4, wherein the converter DC / DC boost is connected to the step-down voltage inverter re- reversible via an isolated high voltage DC bus (270V).

6. Architecture according to any one of claims 3 to 5, in in which the step-down inverter is integrated into an electrical circuit engine power electronics.

7. Architecture according to any one of the preceding claims, in which the upstream conversion device is sized for compensate for energy loss in the supercapacitor due to currents leak.

8. Architecture according to any one of the preceding claims, in which the onboard electrical network delivers a direct current voltage (28V), the upstream conversion device comprising a converter continuous / continuous.

9. Architecture according to claim 8, wherein the device of The upstream conversion is designed to be reversible and to have a function voltage step-down and a voltage step-up function to allow energy distribution from the supercapacitor to the grid on-board electrical system.

10. Architecture according to any one of claims 1 to 7, in which the onboard electrical network delivers an alternating voltage (115V), the upstream conversion device including a rectifier passive simple alternating current or a rectifier with factor correction of power.

11. Architecture according to any one of the preceding claims, in which the supercapacitor is connected to the conversion device upstream and downstream conversion device via a high-voltage bus continuous (270V).

12. Architecture according to any one of claims 1 to 10, in to which the supercapacitor is connected to the upstream conversion device and to the downstream conversion device via a low-voltage DC bus (28V).

13. Architecture according to any one of the preceding claims, in which the supercapacitor, the function management circuit- operation of the supercapacitor, the upstream conversion device and at least part of the downstream conversion device are part of a same electronic device incorporating a processor.

14. Architecture according to any one of the preceding claims, in which the supercapacitor is sized so as not to be fully charged for a period of aircraft flight time.

15. Architecture according to any one of the preceding claims, in which a power dissipation resistor is connected to downstream conversion device to dissipate the energy produced when the The engine is in generator operating mode and the supercon- The densifier is saturated.

16. Aircraft comprising a three-phase onboard electrical system and a network single-phase on-board electrical system, the latter being part of an ar- actuator power supply architecture according to any one of the re- previous demands implemented in the aircraft to power aircraft actuators.