Design of an energy function based fuzzy tuning controller for HVDC links

The paper introduces an energy function based fuzzy tuning method for the c ontroller parameters of an HVDC transmission link. The test system, a point to point DC link, was subjected to various small and large disturbances to examine the effectiveness of the proposed method. The DC current error and its derivative are taken as the two principal signals to generate the chan ge in the proportional and the integral gains of the rectifier current regu lator according to a fuzzy rule base. Computer simulation results confirm t he superiority of the proposed adaptive fuzzy controllers over the conventi onal fixed gain controllers in damping out the transient oscillations in HV DC links connected to weak AC systems. (C) 1999 Elsevier Science Ltd. All r ights reserved.