Subtransmission grid control via online feedback optimization

The increasing electric power consumption and the shift toward renewable energy resources demand for new ways to operate transmission and subtransmission grids. Online Feedback Optimization (OFO) is a feedback real-time control method that can be employed to enable optimal operation of these grids. Such controllers can maximize grid efficiency (e.g., minimizing curtailment) while satisfying grid constraints like voltage and current limits. The OFO control method is tailored and extended to handle discrete inputs and it is explained how to design an OFO controller for the subtransmission grid. A novel benchmark is presented and published that corresponds to the real French subtransmission grid on which the proposed controller is analyzed in terms of robustness against model mismatch, constraint satisfaction, and tracking performance. It is shown that OFO controllers can help utilize the grid to its full extent, virtually reinforce it, and operate it optimally and in real-time by using the flexibility offered by renewable generators connected to distribution grids. • Subtransmission grid can be operated optimally in real-time using online feedback optimization. • Online feedback optimization allows minimizing curtailment and losses while satisfying grid limits. • A new benchmark based on a real French subtransmission grid is publicly available. • Online feedback optimization can handle discrete grid actuation. • Online feedback optimization maintains grid constraint satisfaction even under model inaccuracies.