Load Dispatch optimization using Dynamic Rating and Optimal Lifetime Utilization of Transformers

Power transformers are critical power system components that are generally loaded conservatively, resulting in marginal utilization of their designed lifetime. Dynamic Transformer Rating (DTR) increases the utilization of this asset by limiting its Hot Spot Temperature (HST) rather than the per unit load, thereby increasing available network capacity. However, residual lifetime would still be unutilized according to current dimensioning criteria and state-of-the-art lifetime aging models. This paper proposes a novel methodology for DTR, where both thermal and aging dynamics are accounted for in a multi-period DCOPF formulation. Power losses are accounted for by means of an iterative approach that preserves convexity of the optimization problem. The proposed methodology leads to an optimal lifetime utilization of transformers and favours the integration of wind power generation. This novel DTR approach can be beneficial for applications with limited asset lifetime like offshore windfarms or for postponing grid reinforcements for short period of time.