Thrust reverser control system
A control system for a thrust reverser with a movable cowl includes an electromechanical actuator to actuate the movable cowl, an electric drive unit (M) driving the actuator, and a power control unit capable of controlling the electric drive unit (M). The power control unit moves the movable cowl to a closed position and/or to a deployed position. In particular, the control system includes an electronic circuit for electric braking capable of braking the electric drive unit (M), in case of overspeed of the drive unit when the movable cowl is moved to the closed position and/or to the deployed position.
1. A control system for a thrust reverser with moveable elements, the control system comprising:
at least one electromechanical actuating member of said moveable elements;
an electric driving unit of said electromechanical actuating member;
a control unit; and
a power control unit to control the electric driving unit for moving the moveable elements to a closing position and/or to a deployed position,
wherein the control system further comprises an electric braking electronic circuit that automatically and electronically brakes the electric driving unit when the electric driving unit experiences overspeed during a displacement of the moveable elements to the closing position and/or to the deployed position.
2. The control system according to claim 1 , wherein the control unit is configured to pilot the electric braking electronic circuit when a speed of the electric driving unit is higher than a threshold speed, in generator or electric driving unit motor mode.
3. The control system according to claim 2 , wherein a value of the threshold speed is a function of a position of the electromechanical actuating member driven by the electric driving unit in its displacement to its closing position and/or to its deployed position.
4. The control system according to claim 1 , wherein the electric braking electronic circuit is configured to suspend any control of the electric driving unit and to regulate a speed of the electric driving unit as to attain a predetermined minimum speed set point.
5. The control system according to claim 1 , further comprising one or several ends of travel stops for the electromechanical actuating member fashioned for stopping the electromechanical actuating member after the electric driving unit has attained a minimum speed set point.
6. The control system according to claim 4 , wherein the electric braking electronic circuit is controlled as long as the minimum speed set point has not been attained by the electric driving unit.
7. The control system according to claim 1 , wherein the electric braking electronic circuit comprises at least one electric energy dissipation device mounted, in series, with a two-state switch, one of two states being suited for connecting the electric driving unit to the energy dissipation device and a rectifier of which an input voltage is formed from an output signal of a power circuit of the electric driving unit.
8. The control system according to claim 7 , wherein the electric energy dissipation device is a power resistor.
9. The control system according to claim 7 , wherein the rectifier is a diode bridge circuitry with natural commutation.
10. The control system according to claim 7 , wherein the power circuit comprises one or several power converters of undulator type configured to output three-phase signal voltage.
11. The control system according to claim 1 , wherein the electric driving unit is associated with state detectors and speed sensors, which identify any loss of control of the electric driving unit.
12. The control system according to claim 1 , wherein the electric driving unit is a reversible alternator which operates in an alternator mode, and is an electric motor which operates in a starter mode.
13. A nacelle comprising at least one moveable element and a control system according to claim 1 .