Nodal Pricing Comparison between DCOPF and ACOPF: Case Studies for the Power Systems in Iceland and Germany

This paper considers the nodal pricing comparison between using the direct current optimal power flow (DCOPF) and the alternative current optimal power flow (ACOPF) models. Two case studies for Iceland and Germany are conducted to illustrate the pricing differences for various load and network congestion scenarios. We also demonstrate the statistical probability distributions of the nodal prices using DCOPF and ACOPF under the considered scenarios. For the case study in Iceland, we use a representative transmission network with 108 nodes, 31 generators and 123 transmission lines. For the case study in Germany, there are 231 nodes, 82 generators and 304 transmission lines. The numerical results show that there can be significant nodal price differences between DCOPF and ACOPF when the power loads are heavy or the power networks are congested. The statistical probability distribution of the nodal prices also show prominent differences for both Iceland and Germany when the power networks are heavily congested.