Generator Tripping Control to Uphold Transient Stability of Power Grid Outwards Transmitting Thermal-Generated Power Bundled With Wind Power

The putting into operation of energy base,where wind power is bundled with thermal-generated power,can bring great economic benefits,meanwhile it will also leads to the variation of both security and stability in the power grid located in the energy base.It is hard to ensure stable operation of the power grid by only tripping conventional thermal generation units after certain serious faults or the cost of tripping conventional thermal generation units is too high.In allusion to it,firstly,the difference between the transient characteristics of thermal generation units and that of wind power generation units as well as the impacts of the two kinds of transient characteristics on system transient stability are analyzed;secondly,it is pointed out that there are two main reasons causing post-fault system instability: one of them is the accelerating energy produced during fault process and the another one is the sharp decline of the capability of outward power transmission system due to the weakening of outward power transmission channel;thirdly,an optimal scheme for tripping thermal units and wind power units after the serious faults is proposed.Simulation results of a certain energy base in West China,where the thermal-generated power is bundled with wind power,show that under the premise of ensuring post-fault secure and stable operation of the power grid,using the proposed optimal generator tripping scheme the quantity of generators to be tripped can be evidently reduced and the restoration characteristics of post-fault power grid can be improved,thus both security and economy of the power grid can be obviously enhanced.