Real-time estimation of power system oscillation period

After discussing the conceptions of power system average frequency and power system oscillation period, this paper analyzes the characteristics of current near the center of oscillation and the relation between real oscillation period and unbalance of current-change, which is derived from the presumed oscillation period. This paper presents a new method for estimating the oscillation period of power system. Some simulations are given for evaluating the influences by system case, harmonics, random noises and oscillation period-change. The results indicate that this method is much precise for estimating the power system oscillation period and will not be influenced by the difference of system cases. It also responds quickly after the oscillation period changed.