A VSC-HVDC Fuzzy Controller for Improving the Stability of AC/DC Power System

This paper puts forward an auxiliary fuzzy logic controller for the Voltage Source Converter based HVDC transmission system, VSC-HVDC, to improve the stability of the AC/ DC system by damping the oscillation effectively after disturbance. The fast control capability of the VSC-HVDC and the process of area mode oscillations are analyzed. No detailed model of the system is required for the design of the proposed control scheme. The controller judges the operation states and the control effect and accordingly adjusts its active power order in an adaptive way by using fuzzy rules, so as to damp out the area mode oscillation. Simulation results on the IEEE 4-generator AC/DC power systems have shown that the controller can enhance the dynamic stability of interconnected power systems effectively and is robust to the variation of system operating conditions and oscillation modes.