Real-time scheduling of electric vehicles charging in low-voltage residential distribution systems to minimise power losses and improve voltage profile

• Published in: IET generation, transmission & distribution Vol. 8; no. 3; pp. 516 - 529
• Main Authors: Luo, Xiao, Chan, Ka Wing
• Format: Journal Article
• Language: English
• Published: Stevenage The Institution of Engineering and Technology 01.03.2014; Institution of Engineering and Technology; The Institution of Engineering & Technology
• Subjects: Applied sciences; battery powered vehicles; binding constraint; Charging; circuit loss; distribution feeder; distribution networks; Disturbances. Regulation. Protection; Electric potential; electric vehicle charging; Electric vehicles; Electrical engineering. Electrical power engineering; Electrical power engineering; electrical safety; EV charging; Exact sciences and technology; Ground, air and sea transportation, marine construction; Level (quantity); losses; loss‐minimisation‐oriented; low‐voltage residential distribution system; Miscellaneous; Operation. Load control. Reliability; Penetration; power grid; power grids; power losses minimization; Power networks and lines; Real time; Road transportation and traffic; scalable real‐time scheduling scheme; Scheduling; Simulation; Voltage; voltage drop; voltage profile improvement; voltage safety margin; voltage‐safety‐oriented; electrical safety; battery powered vehicles; distribution networks; power grid; voltage-safety-oriented; losses; electric potential; voltage profile improvement; circuit loss; loss-minimisation-oriented; voltage safety margin; electric vehicle charging; distribution feeder; EV charging; scheduling; voltage drop; binding constraint; power grids; low-voltage residential distribution system; power losses minimization; scalable real-time scheduling scheme; Performance evaluation; Load distribution; Scalability; Peak load; Voltage fall; Power system stability; Daily variation; Scheduling; Electric vehicle; Low voltage; Electrical network; Power losses; Voltage stability; System simulation; Planning; Safety; Real time processing; Effectiveness factor; Distribution network; Voltage distribution
• ISSN: 1751-8687; 1751-8695; 1751-8695
• DOI: 10.1049/iet-gtd.2013.0256

Unscheduled charging of plenty of electric vehicles (EVs) might exert an adverse effect on the existing power grid, especially when the charging coincides with daily peak load at distribution level. In this study, a scalable real-time scheduling scheme for EV charging in low-voltage residential distribution system is proposed. Since most often, voltage drop would become a binding constraint when a distribution feeder is subject to a high EV penetration level, a scheduling method is first developed to increase the voltage safety margin. Then, a novel factor is derived to allow the scheduling to shift from voltage-safety-oriented to loss-minimisation-oriented, or vice versa, on demand of the EV penetration level. A number of charging scenarios were simulated to evaluate the proposed scheduling scheme. Simulation results verified that the proposed scheduling scheme is fast and efficient with circuit losses close to optimal at a low EV penetration level and voltage drops maintained within the tolerable limit at a high EV penetration level. The high scalability and effectiveness of the proposed scheme has made it suitable for coordinating large number of EV charging activities in real-time.