Risk-Based Coordination Research on Prevention Control and Emergency Control of Quasi-Steady State AC-DC System

Modern power system is becoming increasingly larger AC-DC hybrid system, and its operating mode is more and more complex. Occasional incidents may cause overload problems, voltage problems, and cascading failures. These problems may damage the system stability. Therefore, in the normal state of the system, it is important to study the state transition and its harm to the system through security analysis. Besides, adopting certain control measures to reduce the risk of the system, such as the coordination of prevention and emergency control, is of great significance to both the safety and the economy of the system. In this premise, this paper proposes a risk-based two-layer optimization model for coordination on prevention control and emergency control of quasi-steady state AC-DC system. By introducing a continuous derivable function, the non-derivable constraints in the traditional model are replaced by continuous derivable constraints. The method can greatly improve the computational efficiency of the model. According to the characteristic of the two-layer optimization model, the first layer optimization problem is solved by the golden section method, and the second layer optimization problem is solved by the active and reactive power alternating approach method. Finally, the effectiveness of the proposed method is verified with simulation example.