Flexible variable-structure control for BLDCM in aero electric actuator

One of the key elements for the aero electric actuator(EA) systems is the electric motor, the current generation systems typically use permanent magnet brushless motors, The performances of brushless DC motors(BLDCM) will directly restrict the performances of EA. A flexible variable structure(FVS) controller was designed to improve the dynamic and static performance of BLDCM. For the large state vectors, a linear control is employed to regulate. For the moderate state vectors, the nonlinear component is blended into the control signal. For very small excursions of the state vectors, the nonlinear component becomes linear component, and regulation is accomplished employing two linear controls. The simulation results show that the controller designed by the proposed method obviously improves the dynamic and static performance of BLDCM. Furthermore the control signals are smooth.