High-performance controllers for HVDC transmission links

The paper presents the design of a very simple fuzzy logic controller for HVDC transmission links for fast stabilisation of transient oscillations. The performance of this controller is compared with variable structure and adaptive controllers for a variety of short circuits and system operational changes. Unlike both adaptive and VSS controllers which require at least functionally an accurate model of the system dynamics, the fuzzy controller does not require a mathematical model of the system to estimate the control input under disturbance conditions. The transient simulation studies presented reveal the superior performance of the simple fuzzy controller in damping out system transients