Study on power system separation based on the local electrical quantities

The paper proposes two new separation schemes based on the local electrical quantities. The first scheme is called "P-Q sign" method, which utilizes the active power and reactive power of the tie line to exactly detect the out-of-step in time. The second is modified from the widely used "compensating principle" for separation, which overcomes the limit that the settings aren\´t easy to design. Those two schemes cooperate with each other to supply for the power system separation effectively. Finally, the arithmetic is verified by the simulation of two-machine-five-bus system.