Trajectory sensitivity-based emergency load shedding optimal algorithm

Huge power transmitted over long distance through some crucial lines increases the probability of a sudden loss of bulk power in the power-receiving system. To prevent such emergency from deteriorating the security of the system, an emergency load shedding model, whose objective is to minimize the total load shedding cost, is built, and then an efficient algorithm is proposed based on trajectory sensitivity. The constraints of the model include transient voltage security, transient frequency security and available load that can be shed. This problem is a large scale, nonlinear programming problem with constraints considering time-varied parameters. The mathematical model is simplified by linearizing the security constraints through trajectory sensitivity, and the consistency of the solution is guaranteed by iterative calculation. The trajectory sensitivity is utilized in guiding the search direction and accelerating the solving process. A provincial power system is used to test the validity of this algorithm.