Research on the control method for the start of microturbine generation system

The sensorless control method for the high speed permanent magnet synchronous machine without position and speed sensor in the start process of a 30 kW microturbine generation system is investigated in this paper. The open-loop speed control mode based on current control is applied at low speed, and the closed-loop sensorless vector control mode is used at medium and high speed. The rotor position and speed estimation algorithm is implemented using an open-loop observer based on back-EMF in the vector control. On the basis of detailed description of the proposed start-up strategy, the simulation and experimental system has been built. Several critical issues were analyzed, including the setting method of the reference speed profile in open-loop mode and the transition time selection from open-loop mode to closed vector control. The simulation and experimental results demonstrate the proposed sensorless control method can meet the requirements of the start process for microtubine generation system, and possesses high static and dynamic performance at large-scale speed.