DAMPING ENHANCEMENT BY ROBUST TUNING OF SVC CONTROLLERS IN THE PRESENCE OF LOAD PARAMETERS UNCERTAINTY

The paper explores the influence of power system loads on static VAr c ompensator (SVC) damping effectiveness. Equipped with properly tuned a dditional stabilizers SVCs have been successfully used for improving t he damping of electromechanical oscillations in power system. The damp ing improvement is usually achieved through indirect voltage influence through voltage dependent loads. Tuning of an additional compensator stabilizer (ACS) traditionally assumes that loads are statically volta ge dependent. However load parameters are generally uncertain and load s often exhibit some dynamic response. This uncertain dynamic behaviou r of loads can introduce an additional phase shift between voltage and load response and such can detune the ACS. Examples of detuning effec ts of dynamic loads as well as robust tuning of ACS are presented and discussed.