Abstract:As the large-capacity generator develops, in order to avoid impact on the grid as well as the unit itself during startup, static frequency conversion system has been used in the field of frequency conversion start of large synchronous motor. Based on the static frequency conversion start system of gas turbine, this paper analyzed how to use electrical detection method to calculate the initial position of the rotor without installing the position sensor. The method is simple, convenient and reliable, which has passed validation on the dynamic simulation experiment platform.