Distributed coordination for economic dispatch with varying load and generator commitment

This paper considers the economic dispatch problem for a group of power generating units. The collective aim is to meet a power demand while respecting individual generator constraints and minimizing the total generation cost. Assuming that the units communicate over a strongly connected, weight-balanced digraph, we propose a distributed coordination algorithm that provably converges to the solution of the dispatch problem starting from any initial power allocation. Additionally, we establish that the proposed strategy is robust against mismatch between load and total generation (and thus able to handle time-varying loads), and against intermittent generation commitment, a plausible scenario due to the integration of renewable energy sources into the grid. Our technical approach uses notions and tools from algebraic graph theory, nonsmooth analysis, set-valued dynamical systems, and dynamic average consensus. Several simulations illustrate our results.