Study of Simplified Models for Transient Frequency in Power Systems

In modern grids, more components such as renewable resources, distributed generators or storages will be integrated into power systems. Thus, transient frequency analyses in such a system become more challengeable. Many factors would affect the transient frequency response of a power system, including synchronous inertia from conventional synchronous machines, dynamic motor loads, the characteristics of speed governor, frequency regulation by power electronic-based resources and others. However, the dynamic parameters of these devices could be inaccurate, which causes a large error for evaluating transient frequency characteristics. Thus, this study investigated various structures of simplified models for transient frequency responses and the corresponding process to establish these models. In addition, this study develops a simplified frequency-response model in Taiwan by considering the collected phasor measurement unit (PMU) data during grid contingencies.