Control and Stability of Low Inertia Systems Using Wind Power Plants

In modern society, the sustainable development is an ongoing theme in response to the targets of energy conservation and carbon emission reduction. The penetration of the renewable energy sources, such as wind turbines and PV, is rapidly increasing in the power system. However, the rapid integration of the renewable energy sources will bring in some low inertia issues, which will have adverse impacts on power system stability. In order to utilize the hidden inertia from the renewable energy sources for system frequency regulation, some synthetic inertia techniques have been proposed, such as synthetic inertia emulation from wind turbines, synthetic inertia emulation from HVDC systems, and synthetic inertia emulation from energy storage. This project aims to assess the impacts of synthetic inertia emulation from the DFIG based wind turbine on system frequency stability in future low inertia power system. The chosen test model in MATLAB is a power system connected by a DFIG based wind farm model. In order to realize the system frequency measurement, the test model will be modified first by adding some other controllers, such as governor controller. Then, the modified test model will be further simplified in order to make its structure simpler and apply to larger power system. Based on the simplified test model, the impacts of three factors, which are synthetic inertia constant, sudden load increase and noise & filtering, on the system frequency responses will be assessed. Finally, the modified test model will be applied to the GB equivalent large system. In this project, it will be verified that the impacts of synthetic inertia emulation form the DFIG based wind turbine on frequency stability are quite significant in future low inertia system.