Session 2: Advanced Technologies to Enhance DER and EV integra9on Antonio ómez-expósito (with contributions by J.M. Maza) IEEE European Public Policy Working roup on Energy October 17, 2016 University of Seville, Spain
Contents 1. Mo%va%on 2. Power flow & voltage control by DFACTS 3. Case study I: enhanced PV integra%on 4. Case study II: fast EV charging 2 Session 2: Advanced Technologies to Enhance DER and EV integration
Mo9va9on Urban feeders: Few laterals 66-110 kv 10-25 kv Distribu9on substa9on Radially operated (normally-open switches) Spare feeder capacity (temporary support under faults) Designed and operated for unidirec9onal power flows Passive loads: rela%vely low simultaneity coefficients (oversized feeders)
Mo9va9on DER and EV: Bidirectional power flows Much higher simultaneity coefficients 66-110 kv 10-25 kv Distribu9on substa9on Congestions: EV Ampacity Overvoltages Primary transformer D
Street digging to upgrade underground MV/LV cables Mo9va9on
Advanced Technologies to Enhance DER and EV integra%on What do we exactly mean by smart grids?
Power flow and voltage control by DFACTS Smart (asynchronous) links: Replace (normally open) mechanical switches by fully controllable electronic switches MV busbar EV D DC link
Asynchronous links between radial feeders: Back-to-back PWM Voltage Source Converters (VSC) P loss Three degrees of freedom: P, Qm, Qn Short-circuit levels not affected (fast response) Same frequency, small voltage drop
Voltage control by solid-state tap changers Replace (fixed) off-load tap changers of secondary distribution transformers by electronic switches ±2,5% ±5%
Solid-state tap changers on MV side: Controllable voltage magnitudes on the LV side (discrete steps) MV busbar EV D
Case study I Integration of distributed renewables Base case P1 + P3 = 8.2 MW
Case study I Integration of distributed renewables 3 control variables 2.7 MW Base case P1 + P3 = 8.2 MW Smart link added (3 MVA) P1 + P3 = 9.8 MW + 19.9 %
Case study I Integration of distributed renewables 8 control variables Base case P1 + P3 = 8.2 MW Smart link added P1 + P3 = 9.8 MW Smart link and tap changers P1 + P3 = 10.5 MW + 28.4 %
Case study II Fast EV charging in LV networks Conventional scheme Smart link-based solution Individual VSC are replaced by parallel VSC with a common DC bus
Case study II Fast EV charging in LV networks Conventional scheme Smart link-based solution Benefit 1 Feeder equalization Minimal losses PT1 PT2
Case study II Fast EV charging in LV networks Conventional scheme Smart link-based solution Benefit 1 Benefit 2 Feeder equalization Minimal losses Transformer below rated power Optimal use of assets ST1
Case study II Fast EV charging in LV networks Conventional scheme Smart link-based solution Benefit 1 Benefit 2 Benefit 3 Feeder equalization Minimal losses Transformer below rated power Optimal use of assets Voltage within regulatory limits Improved power quality V13
REFERENCES T. önen, Electric Power Distribution System Engineering, CRC Press, 2008. A. ómez-expósito, J.M. Maza-Ortega, E. Romero-Ramos, A. Marano-Marcolini, Enhancing the Integration of Renewables in Radial Distribution Networks Through Smart links, Smart rid Infrastructure and Networking, pp. 155-179, CRC Press. 2012. ISBN 978-0-07-178774-1. E. Romero-Ramos, A. ómez-expósito, A. Marano- Marcolini, J.M. Maza- Ortega, J.L. Martínez-Ramos, Assessing the loadability of active distribution networks in the presence of DC controllable links, IET en., Trans. and Dist., vol. 5, no. 11, pp.1105-1113, 2011. J.M. Maza-Ortega, A. ómez-expósito, M. Barragán-Villarejo, E. Romero- Ramos, A. Marano-Marcolini, VSC-based topologies to further integrate renewable energy sources in distribution systems, IET Renewable Power eneration, vol. 6, no. 6, pp. 435-445 2012. F.P. arcía-lópez, M. Barragán-Villarejo, J.M. Maza-Ortega, A. ómez- Expósito, Multiterminal electrical charging station for LV networks. IEEE PES PowerTech 2015. Eindhoven (The Netherlands), June 2015. M. Barragán-Villarejo, A. Marano-Marcolini, F.P. arcía-lópez, J.M. Mauricio, J.M. Maza-Ortega, Coordinated Control of Distributed Energy Resources and Flexible Links in Active Distribution Networks, 4th IET International Conference on Renewable Power eneration. Beijing (China). October 2015.
Session 2: Advanced Technologies to Enhance DER and EV integra9on Antonio ómez-expósito (with contributions by J.M. Maza) IEEE European Public Policy Working roup on Energy October 17, 2016 University of Seville, Spain