Blackout Model Considering Slow Process

In this paper a blackout model that considers the slow process at the beginning of blackouts is proposed based on the improved ORNL-PSerc-Alaska (OPA) model. It contains two layers of iteration. The inner iteration, which describes the fast dynamics of the system, simulates the power system cascading failure, including the tree contact and failure of lines caused by heating. The simulation of protective relays and the dispatching center is also improved to make it closer to practical conditions. The outer iteration, which describes the long-term slow dynamics of the system, adds the simulation of tree growth and utility vegetation management (UVM). Typical blackout process with slow process is simulated on the Northeast Power Grid of China and self-organized criticality (SOC) characteristic of this system is analyzed with the proposed model. The effectiveness of the proposed model is verified by the simulation results.