Out-of-step Splitting Control based on Network Wide Area Response Information

Abstract

Influenced by the continuous growth of renewable energy installation scale and the increasingly prominent characteristics of AC/DC hybrid structure, the disturbance behavior of large power grid is becoming more and more complex. To ensure the safety of power grid, higher requirements are put forward for the reliability, accuracy and orderliness of the out-of-step splitting control which is belonged to the third line of defense. Firstly, this paper analyzes the principle and application limitation of out-of-step splitting control of ucosφ based on local measurement information, studies the relationship and error between ucosφ and oscillation center, and the location coefficient ζ of oscillation center is defined. On this basis, the criteria of branch splitting and the control strategy of multi-branch wide area cooperative out-of-step splitting are proposed. The simulation results of AC and HVDC hybrid power grid show that the proposed strategy can adapt to the complex dynamic behavior of large power grid in which multiple generator clusters lose synchronization one after another, accurately identify the cutset corresponding to the out-of-step generator cluster, and realize the unified and orderly splitting of each branch in the cutset.