A simulation-based linearity study of large-scale power systems

The power system is a typical complex and nonlinear system in nature. Theoretically, the nonlinear approach can describe a dynamic system more accurately than a linear approach, but to an actual power grid, a linear approach was usually used to model a nonlinear problem approximately. To investigate when the system can be linearized and “how small is small” to linearize the system accurately, this paper proposed a measurement-based linearity study approach based on the linear system theory, which utilizes the dynamic responses after events in the actual U.S. Estern Interconnection (EI) power grid and the North-Central China power grid.