Optimal Control Time of Emergency Control to Damp Power System Low-Frequency

When the low-frequency power oscillation occurs in the power system, dispatchers often adopt the emergency control method of reducing output and load to suppress the oscillation as soon as possible, so as to maintain the stability of the system. This paper proposes and studies the optimal control time of the emergency control. The importance of controlling time selection to suppress oscillation is proposed and demonstrated when emergency control is applied. This paper presents an algorithm for calculating the optimal emergency control time, calculates the optimal emergency control time of the demonstration example, finds the relation between the optimal emergency control time and the time when the line power oscillation reaches the maximum and minimum amplitude, and explains the observed rule by using the Equal Area Criterion, and deduces the conclusion. Finally, through an example of a complex multi-machine power system, the results of the optimal emergency control time calculation and the nonlinear simulation verify the conclusion of the relationship between the optimal emergency control time and the maximum and minimum amplitude time of power oscillation.