Publication detailsRenedo, J., Ibrahim, A. A., Kazemtabrizi, B., Garcia-Cerrada, A., Rouco, L., Zhao, Q. & Garcia-Gonzalez, J. (2019). A simplified algorithm to solve optimal power flows in hybrid VSC-based AC/DC systems. International Journal of Electrical Power and Energy Systems 110: 781-794.
- Publication type: Journal Article
- ISSN/ISBN: 0142-0615
- DOI: 10.1016/j.ijepes.2019.03.044
- Further publication details on publisher web site
- Durham Research Online (DRO) - may include full text
Author(s) from Durham
High Voltage Direct Current systems based on Voltage Source Converters (VSC-HVDC) are increasingly being considered as a viable technology with advantages, above all when using underground or submarine cables, for bulk power transmission. In order to fully understand how VSC-HVDC systems can be best used within existing power systems, it is necessary to adapt conventional tools to carry out system-wide studies including this technology. Along this line, this paper proposes a simplified algorithm to solve optimal power flows (OPFs) in hybrid VSC-based Alternating Current/Direct Current (AC/DC) grids with multi-terminal VSC-HVDC systems. The proposed algorithm makes it possible to seamlessly extend a previous large-scale AC case to which several multi-terminal VSC-HVDC systems must be added. The proposed approach combines two ideas used previously in two different modelling approaches: each VSC is modelled as two generators with a coupling constraint; and DC grids are modelled as notional AC grids, since, in per unit, the equations for the former are a particular case of the latter with resistive lines and no reactive-power injections. In the proposed approach, the hybrid VSC-based AC/DC system is transformed into an equivalent only-AC system. Therefore, the OPF solution of the AC/DC system can be found with the same tool used for the previous AC problem and a simple extension of the original case.