Speed sensorless control with extracting high-frequency current signal from rotor of electrically excited synchronous motor.

Rotor position identification model based on high-frequency voltage signal injection of electrically excited synchronous motor was built, and the extraction filter design of induced current signal, which contains the rotor position information, with stator and rotor windings injecting into high-frequency voltage signal was analyzed. On the basis of that, the stator q-axis high-frequency voltage injection was proposed and motor's high-frequency induction current was used to identify the rotor position angle. A specific frequency notch filter and high cut-off frequency low-pass filter were designed for the harmonic content distribution characteristics of rotor current supplied with thyristor controlled rectifier, to realize rapid extraction of rotors effective high-frequency current. The rotor position and speed information was obtained by using SPLL to realize wide range speed sensorless control of electrically excited synchronous motor. It's proven that the proposed control scheme, which has good low-speed performance and fast torque response, is simple and easy to achieve by experiment results. [ABSTRACT FROM AUTHOR]