A Novel Formulation to Compute Sensitivities to Solve Congestions and Voltage Problems in Active Distribution Networks

Sensitivities are broadly appreciated because of its simplicity and good results in solving voltage problems and congestions in transmission networks. However, since sensitivity calculation is based on a linear approximation of the power flow equations, all decisions commit an intrinsic error that might lead into unexpected results, especially in distribution networks. This paper analyzes the error associated to sensitivities considering a wide range of control variables and proposes a novel formulation to extend the use of sensitivities to manage congestions in active distribution networks. First, a theoretical analysis is performed to study the origin and propagation of errors. Then, numerical results are presented for two types of distribution networks (20 kV and low voltage grids). Finally, a novel formulation is proposed to extend the use of sensitivities to manage congestions, which will allow to reuse previous sensitivity-based methodologies to solve both voltage problems and congestions in active distribution networks.