Abstract: The classification of power system operating states plays an important role in power system control and operation. Determining the state of power system is crucial and requirements for the real time decision making in power system security assessment demand low dimensionally and low computational time. In this paper I have tried to explain all the operating states of power system along with the state transition diagram which comprises of five different states. The main purpose of both of these that is operating states and the state transition diagram is for the power system security. The power system needs to be secured. We need to protect it from the black out or any internal or external damage. The operation of power system is a set to be normal only when the flow of power and bus voltages are within the limits even though there is a change in the load or at the generation side. From this we can say that the security of the power system is an important aspect with respect to the continuation of its operation.

Keywords: Preventive state, Restorative state, Emergency state, Normal State, Alert State and Extreme State.

| DOI: 10.17148/IJIREEICE.2021.9724