A model to defense cascading failures in complex power grid based on multistage games with incomplete information

To defense the blackout caused by cascading failures, based on multistage games with incomplete information a model to defense cascading failures in complex power grid is proposed. Seeing that the failure-state information in different stages of cascading failures cannot be mastered, it is proposed to characterize the affects of component faults on power grid under incomplete information by the severity degree of overloading and the severity degree of voltage drop. Combining with game theory, the proposed model recognizes the offensive side's current strategy during different courses of cascading failures and gets the payoff function. According to payment function values, the defensive side takes appropriate defense strategy by calculating the DC power flow sensitivity matrix and load node voltage sensitivity matrix, meanwhile, the overloading coefficients of power grid components are rapidly calculated to predict the offensive side's strategy in the next round. The proposed model provides direct and accurate evidences for adjustment measures at the initial stage of cascading failures and emergency control measures at the rapid spreading stage. The feasibility and effectiveness of the proposed defense model are validated by case simulation.