Estimate of power-frequency characteristics in power systems by using normal operating data

It is demonstrated that normal operating data in power systems may be used to determine power-frequency characteristics. Both generator and load power-frequency characteristics are estimated as transfer functions, using spectral analysis techniques. Generator characteristics can be determined as a transfer function of a two-input-single-output linear system. Although there is some difficulty in estimating load characteristics, it is shown that the estimate is given as a transfer function of the system with output measurement noise. The results of a simulation study indicate that the methods described are effective for estimating power-frequency characteristics