A new self-tuning robust PI cotroler for HVDC systems
H. R. Najafi, A. Shoulaie, F. Robinson and M. R. Jahed Motlagh
The design implementation of a new self-tuning fuzzy-based robust controller for basic dc controls in an HVDC system is presented. The fuzzy logic approach uses rules based primarily on simple logical reasoning to adaptively adjust the controller gains, and time constants of a single PI controller. Also, a fuzzy control-mode changer is implemented and applied for smoth transition from one control mode to another. Error signals and their derivative are input to the fuzzy system to give optimum system perfornance under various normal and abnormal conditions. simulation results verify improved performance of proposed controller compared to the conventional PI controller under various operating conditions.