Autonomous damping controller design for power system oscillations

This paper concerns the use of the autonomous concept of control structures to design damping controllers in large power systems. The concept is to use hierarchical structures in conjunction with a power system stabilizer (PSS) to add damping to the system. The term autonomous refers to self-governance and independent operation, including the case of uncertainty in input data and partial controller failure. The autonomous control concept adds considerable system strength and allows some measure of self-healing of the interconnected power system. The traditional PSS is the local control of generators, utilizing local signals such as frequency, accelerating power and speed deviation. However, if wide area, remote signals are added to these inputs, it may be possible to develop a higher level controller with superior small-signal stability characteristics. A possible configuration of such a higher level, “super PSS” autonomous structure is suggested in this paper. The objectives of a “super PSS” and relative methods used to achieve these objectives are presented here. The performance of the new design is studied using a two-area, four-generator interconnected power system example