Tripping Control for Transient Stability in Coordinated Hydro and Wind Generation

Over-frequency generator tripping (OFGT) is used to cut off extra generation to balance power and loads in an isolated system. In this paper the impact of OGFT as a consequence of grid-connected wind farms and under-frequency load shedding (UFLS) is analysed. The paper uses a power system model to demonstrate that wind power fluctuations can readily render OFGT and UFLS maloperation. Using combined hydro and wind generation, the paper proposes a coordinated strategy which resolves problems associated with OFGT and UFLS and preserves system stability.