Current research on cascading failure blocking control often neglects the impact of system observability. Cascading failures can degrade the observability of a power system

thereby affecting the formulation of effective control strategies. Therefore

it is necessary to investigate the interactions between system observability and cascading failure blocking control

as well as relevant modeling methodologies. First

the concept of system observability and the process of cascading failures are introduced. Combined with the facts that cascading failures reduce system observability and blocking control strategy is affected by system observability

the correlation between system observability and cascading failure blocking control is analyzed. Then

a cascading failure blocking control model considering the observability of the system is established. Finally

comparative analyses are conducted using the IEEE 39-bus and IEEE 118-bus systems. The results show that the proposed model can effectively reduce the risk of cascading failures and improves the practicability of power system operation. A comparison of the control processes and results

with and without considering system observability

indicates that the influence of unobservability on the blocking control strategy can be partially eliminated by increasing PMU redundancy.