Design of Plug-In Electric Vehicle's Frequency-Droop Controller for Primary Frequency Control and Performance Assessment

Response Accuracy and Tracking Errors with Decentralized Control of Commercial V2G Chargers

“…explicit set-points, or signals containing switching probabilities. In the latter case, the EV will draw a random number and decide to change its set-point or not [5]. However, in these approaches very advanced and reliable real-time communication is required.…”

“…Even though a single EV's capacity is not particularly large compared to generators, if a large number of EVs is controlled by an aggregator, it is possible to offer significant amounts of reserve capacity. The literature proposes aggregate models and control schemes for both centralized [3], [4] and decentralized [5]- [8] solutions for the optimal management of EV fleets performing frequency control.…”

“…In [6] it is shown how demand can respond to frequency deviations in a manner similar to the generators in a purely decentralized way, making it a significant and reliable asset as contribution to PFC. In [5] optimal EV droop curves are designed to improve system stability and in [10] adaptive droops are proposed for EVs offering PFC, to take state of charge (SOC) requirements into account. Finally, [7] proposes a distributed frequency control method, which randomly assigns delays to each EV of the fleet, aiming at avoiding problems to the power system in case of high shares of EVs providing regulation and simultaneous response of all units to the same frequency signals.…”

Large-scale provision of frequency control via V2G: The Bornholm power system case

“…Critical response times of the aggregated EV fleet, as well as the need for each EV to comply with the ISO 15118 technical standard requirement of charging/discharging rate granularity, play an important role when dynamically assessing the response characteristics [16]. In fact, relatively large discrete step responses may trigger frequency stability problems, as presented in the literature within the domain of demand response [17]- [21], and also experienced in an experimental microgrid with smart-charging EVs [22], [23]. The stability of the power system may be jeopardized by V2G EV fleets in case of simultaneous and high ramping-rate responses, especially under large response delays.…”

“…The stability of the power system may be jeopardized by V2G EV fleets in case of simultaneous and high ramping-rate responses, especially under large response delays. The state-of-the-art is lacking of exhaustive contributions on this topic: investigations are proposed only in [20] and in [21]. In Ref.…”