An Online Calculation Method for Optimal Power Flow Based on Optimal Operation Region

With the increasing uncertainties of renewable energy and load variations, the optimal power flow (OPF) needs to be solved in real-time to determine the optimal operation strategy of power systems. However, the efficiency of OPF computations is still a bottleneck, especially for enormous states in the probabilistic analysis. To address this, this paper proposed an online DC-OPF calculation method based on optimal operation region (OOR). Considering the variations of loads and renewable generations, the boundary of OOR is explicitly expressed to divide operation regions. In each OOR, a linear function is constructed to map the relationship between the optimal operation result and variations. In this way, the OPF of different variations is treated as the functional mapping, instead of the time-consuming optimization algorithms. Case studies are conducted on a 5-bus power system and its OOR is given in an explicit expression. The results verify the effectiveness of OOR, which can improve the computational efficiency of OPF considering uncertainties of renewable energy resources and the load variations.