A method for frequency dynamics analysis and load shedding assessment based on the trajectory of power system simulation

A method for frequency dynamics analysis and load shedding assessment is proposed in this paper, which maps the simulation trajectories in the multi-machine space to a single-machine space by using the center-of-inertia transform. This method not only takes advantage of numerical integrationl method, which is not limited by the model, but also uses the concept of uniform frequency of the single-machine model to compensate the shortage of numerical integration method effectively. Therefore, the coefficients calculated based on the method can represent the influencing factors to the frequency dynamics, such as operation modes, network configurations and model parameters of generators and loads, etc. Furthermore, an under frequency load shedding scheme based on the method is proposed for Guangdong power system. The simulation results show that the new scheme has much more adaptability than the traditional UFLS scheme.