Impacts of communication failure on power system operations

Communication technology serves important functions in the power system energy management system (EMS). Recent studies found that cyber-attack and terrorist attack can cause failure of power system communication which affects EMS in various ways. This paper analyzes two impacts of communication failure on EMS, namely, system observability and system control. The first impact on system observability is studied using DC state estimation to identify unobservable states when loss of communication occurs at various locations. The second impact on system control is studied using DC OPF to find the loss of load caused by communication failure. Simulation studies on the two analyses are conducted on IEEE 14 bus and IEEE 30 bus systems. Results show that certain substations are more critical for system observability. Optimal upgrade strategy is provided in this paper to improve system observability. It is also shown that failure of communication will cause extra loss of load. By protecting certain substations, the system can expect less loss of load. It is concluded that communication system is crucial to the power system operation. This paper also gives suggestion to optimally improve communication systems.