Flexible Frequency Operation Strategy of Power System With High Renewable Penetration

Growth of renewable penetration will increase the requirement for flexible resources. It may be a simple solution to build more flexible resources, but it is too expensive. Recently, the new construction of power plant or transmission line has faced opposition by the resistance of the local residents. Depending on the needs, new methodologies are required in order to gain the flexibility of the power grids. This paper proposes the flexible frequency operation strategy with significant renewable penetration to achieve the flexibility of the power grids. Flexible frequency operation provides customized frequency through BTB HVDC, and the overall system is operated with relaxed frequency regulation. By reducing the need and role of the frequency ancillary service reserve, an operator does not need to secure additional governor response reserve for renewable energy. In order to model frequency dynamic of high renewable penetrated power system, the swing equation is modified in this paper. The case studies using MATLAB show effectiveness of flexible frequency operation strategy.