The high efficiency AC servo control system for a missile

This paper focuses on a 2.3 kW AC servo system applied in a missile surface actuation system. Because of limited power capacity, it is necessary to improve the efficiency of the missile equipments including electric motors and their control systems. With the advantages of eliminating field copper loss, higher power density, lower inertia, and higher efficiency, the high-speed permanent magnet synchronous motor is applied. And a comparison between IGBT and power MOSFET based on the characteristic of this system yields that power MOSFET is the ideal switching device for this system. An improved control algorithm is presented in detail. It is developed from the traditional vector control algorithms and SVPWM method for AC motors. Usually, the time the digital system takes to acquire and process the signals are not considered in control algorithm. It results in a control lag especially when the motor runs at high speed. Therefore, control quality is reduced and the stator current drives the motor not so effectively. The new algorithm aims to eliminate the control lag with the purpose of improving the efficiency of the system. Finally, the results of experiments prove that this system achieves high quality and efficiency.