On the behavior of responsive loads in the presence of DFACTS devices

The paper studies a constrained economic dispatch problem in electricity networks with price-dependent demand, and in which the transmission lines are potentially instrumented with DFACTS devices with a view to mitigating system congestion. Specifically, the network objective concerns the joint adjustment of consumption profiles in response to the electricity price and the design of variable reactance (DFACTS settings) that lead to a form of welfare optimization. To this end, the paper introduces an iterative minimization approach that seeks to optimize the constrained dispatch objective through successive (iterative) adjustments of consumption profiles at the responsive loads based on the difference between the price estimated by the loads and the price resulting from the economic dispatch. Simulations demonstrating the efficiency of the proposed approach in the presence of two different types of DFACTS devices are presented on the IEEE 14-bus system. In particular, the numerical findings provide a quantitative understanding of how the presence of DFACTS lead to reduced locational marginal prices and increased demand accommodation capacity in networks of responsive loads.