Coordinated damping control of power systems based on on-line identification

Based on uniform damping thought and identification of low-frequency oscillation (LFO), the paper puts forward design method of multi-band PSS (MBPSS) which makes use of genetic algorithm (GA) and region pole placement method to realize uniform damping control. First, based on characteristics of power systems with uniform damping and essence of damping LFO of PSS, conditions of realizing uniform damping control are deduced, then based on on-line identification and damping evaluation, the control object is chosen. Finally making use of GA and poles placement the damping of LFO is converted into the design and parameter coordination of MBPSS. Because identified models consider influence of other machines and the control goal avoids decreasing damping of other modes in excess, the coordination of controllers is realized. At the same time, the feedback signal of MBPSS is local so decentralized coordinated control is realized. At last, take IEEE 4-machine 11-node system as example, the simulation proves MBPSS designed validity and robust, the method provides a new thought to restrain LFO.