Optimal coordinated EV charging with reactive power support in constrained distribution grids

Document Type

Conference Proceeding

Publication Date



Department of Electrical and Computer Engineering; Center for Cyber-Physical Systems


Electric vehicle (EV) charging/discharging can take place in any P-Q quadrants, which means EVs could support reactive power to the grid while charging the battery. In controlled charging schemes, distribution system operator (DSO) coordinates with the charging of EV fleets to ensure grid's operating constraints are not violated. In fact, this refers to DSO setting upper bounds on power limits for EV charging. In this work, we demonstrate that if EVs inject reactive power into the grid while charging, DSO could issue higher upper bounds on the active power limits for the EVs for the same set of grid constraints. We demonstrate the concept in a 33-node test feeder with 1,500 EVs. Case studies show that in constrained distribution grids, coordinated charging significantly reduces the average cost of EV charging if the charging takes place in the fourth P-Q quadrant compared to charging with unity power factor.

Publisher's Statement

© 2017 IEEE. Publisher's version of record: https://doi.org/10.1109/PESGM.2017.8274266

Publication Title

2017 IEEE Power & Energy Society General Meeting