Defining the adaptability of splitting criterion based on local information in complex and large-scale power grids is of great significance to guiding complex operation and control of power systems. The adaptability of splitting criterion based on phase angle in complex scenarios is studied. The effects of both equivalent machine voltage amplitude ratio and multi-frequency oscillation on phase angle change regulation in the out-of-step oscillation process are analyzed. For the problems identified

the configuration principle and strategies suitable for large-scale power grid is proposed. For an out-of-step oscillation mode with different voltage amplitudes of equivalent electromotive force

the system can be divided into two parts in the oscillation center as decomposition points. When the voltage amplitude is relatively large

the splitting device arranged on the high voltage side cannot correctly identify the out-of-step risk. Existing engineering criterion is suitable for the scenario of the equivalent electromotive force voltage amplitude ratio less than 1.4. On the other hand

the splitting device arranged on the low voltage side cannot correctly judge the out-of-step cycle. In view of the potential risks

measures are put forward for configuring splitting devices on both sides of the oscillation center

using the unified judgment logic of out-of-step oscillation center direction and blocking opposite direction out-of-step judgment logic. The correctness of the improved strategy is verified in a multi-frequency oscillation scenario. This work is supported by State Grid Corporation of China

Major Projects on Planning and Operation Control of Large Scale Grid (No. SGCC-MPLG003-2012).