A privacy-preserving method with flexible charging schedules for electric vehicles in the smart grid

The Smart Grid (SG) is an emerging modernized electrical power system with advanced monitoring and control mechanism, and improved fault-tolerance. Electric Vehicles (EVs), with their energy storage capability, are gaining popularity as an integral part of the energy management system in the SG. To balance the load-demand condition of the grid, EVs are required to schedule a charging event before participation. However, the information transmitted by an EV in charging events can reveal personal information of its owner. The privacy-preserving methods for EVs in existing literature are based on anonymous authentication mechanism, where, missing a charging event by an EV is considered as malicious and the EV is penalized. However, missing a charging event may happen due to many valid reasons and flexibility of scheduling can encourage consumer participation. In this paper, an authentication method is proposed to achieve anonymity and flexibility in charging events for EVs. Additionally, a charging station network setup that divides a large regional area into smaller zones to improve privacy, is proposed. Results based on a MATLAB simulation are presented to demonstrate the Degree of Anonymity (DoA) achieved in different stages of the proposed method, the optimal number of missed charging events, and sub-division of zones.