Different approaches of stationary reference frames saturators

The control of grid voltage and current source converters (VSCs and CSCs) in stationary reference frames by means of resonant controllers is a well-known issue. The corresponding sinusoidal control references should be also limited under anomalous conditions to assure the safe operation of the converter. Present saturators, designed for synchronous reference frames, limit the reference but not its amplitude or phase which distorts sinusoidal waveforms and changes the a priori active and reactive power references. This work is focused on developing different novel techniques achieving different grades of distortion and bandwidth in function of the control loop structure and system requirements. Tools like Kalman Filter (KF), second order generalized integrator (SOGI) and phase-locked loop (PLL) or vector calculus are employed to develop these saturators. Simulation and experimental results are provided to verify the saturators performance in several control systems.