Direct Torque Control for Autonomous Doubly Fed Induction Machine based DC Generator

The paper presents Direct Torque Control method applied in Autonomous Doubly Fed Induction DC-Voltage Generator. The system consists of doubly fed induction generator which stator circuit is connected to dc-link by diode rectifier and rotor circuit converter is connected to the same dc-link. In such system the main problem are large torque oscillations caused by nonlinear stator connected diode rectifier. Autonomous direct torque control is described as a solution able to reduce this drawback with simultaneous control of stator voltage and frequency.