Optimal use of demand response for lifesaving and efficient capacity utilization of power transformers during contingencies

Contingencies of transformers in a multi-unit substation may affect life of healthy units severely due to overloads. This paper proposes a novel demand response (DR) and dynamic thermal rating (DTR) based optimization model for efficient capacity utilization and life management of transformers during contingencies. The model opts for the optimal combination of corrective actions among load curtailment (LC), DR, and shifting load to an adjacent substation while maintaining the winding hot-spot-temperature (HST) under a predefined limit. Simulations are performed, on a typical Finnish two-transformer primary distribution substation as a test system, for case studies of demand with and without DR & two situations based on availability of neighboring substation connection. The obtained results indicate that the proposed model offers substantial benefits of life-saving and utilization improvement for transformers present in different ambient conditions.