Updating System Representation by Trajectory Acquisition in a Dynamic Security Framework

In this chapter, the authors propose an optimization method, based on nonlinear programming, for estimating dynamic parameters of power systems. In the proposed procedure, time–domain simulation trajectories are compared with online measurements to update or estimate dynamic parameters. The main advantage of this method is flexibility because it can be adopted for estimating any parameter, such as synchronous machine constants, external network equivalents, constants for frequency-dependent or voltage-dependent loads. The methodology can be applied during online power system operation and provides more reliable database for real-time dynamic security and control: in fact a frequent update of power system dynamic model can guarantee more reliable simulations and, consequently, more effective control. This is an application that can take advantage of wide-area measurement system (WAMS) framework, because this technology can provide the set of synchronized and normalized measurements that are necessary for implementing the proposed optimization algorithm.