Application of Improved Risk Assessment Technology in Grid Switching Operation

The grid switching operation may cause power system accidents. Dispatchers need to conduct risk assessment on switching operations to enhance the operational security. Currently the dispatchers lack an effective risk assessment method. This paper first proposes a risk index severity function based on improved utility theory, improving the accuracy of the risk severity indicator by setting the slope of the index loss coefficient curve in different overshoot and overload intervals. Then the concept of the optimal risk assessment area unit is proposed, accurately reflecting the impact of a specific operation on the grid by dividing the evaluation area unit to exclude the interference data. The paper also proposes a dynamic risk indicator threshold depending on the optimal risk assessment area unit, which makes the risk assessment focused and discriminative. Finally, the case analysis proves the correctness and feasibility of the proposed method.