Abstract：The traditional control of electromechanical actuator in aviation electromechanical servo system

mostly adopts two-level inverter and PID control，which can not achieve higher precision control of permanent

magnet synchronous motor. In view of the above problems and the difficulty of space vector modulation algorithm

to solve the problem of neutral point voltage balance，a model predictive control method based on improved virtual space vector method was proposed，and the corresponding control strategy was designed. The model predictive control was used to improve the control response speed and control accuracy of the permanent magnet synchronous motor. The neutral point clamped（NPC）three-level inverter with more sinusoidal output was used. The improved virtual space vector pulse width modulation（VSVPWM）was used to construct a dodecagon virtual space vector diagram closer to the vector circle. The simulation results show that the improved method can realize the stable operation of permanent magnet synchronous motor under low torque ripple，and has a good control effect on the midpoint voltage balance problem.

      Key words：three-level inverter；midpoint potential；model predictive control；virtual voltage vector