Stochastic Modeling of EV On-Board Chargers for V2G Services

Vehicle-to-Grid (V2G) applications offer significant potential to support power grids by providing ancillary services through the rapid charging and discharging of electric vehicles (EVs), often within a timeframe of a few seconds. This paper introduces a Markov-chain model to analyze EV on-board systems for V2G applications. The system's states are designed to account for on-board charger communication delays and asymmetric ramping rates. The primary objective of the model is to evaluate the proportion of market signals successfully executed within a defined delay constraint. A case study based on real-world communication delay measurements taken from six distinct EV on-board chargers, as well as sample market signals from PJM, is presented. The findings reveal that communication delays have a considerable impact on the effectiveness of V2G applications, and not all EV models are suitable for providing ancillary services. Consequently, the proposed model serves as a valuable pre-evaluation tool for conducting vehicle-specific assessments, facilitating more effective integration of V2G capabilities in future applications.