Unsplittable Load Balancing in a Network of Charging Stations Under QoS Guarantees

The operation of the power grid is becoming more stressed, due to the addition of new large loads represented by Electric Vehicles (EVs) and a more intermittent supply due to the incorporation of renewable sources. As a consequence, the coordination and control of projected EV demand in a network of fast charging stations becomes a critical and challenging problem. In this paper, we introduce a game theoretic based decentralized control mechanism to alleviate negative impacts from the EV demand. The proposed mechanism takes into consideration the non-uniform spatial distribution of EVs that induces uneven power demand at each charging facility, and aims to: (i) avoid straining grid resources by offering price incentives so that customers accept being routed to less busy stations, (ii) maximize total revenue by serving more customers with the same amount of grid resources, and (iii) provide charging service to customers with a certain level of Quality-of-Service (QoS), the latter defined as the long term customer blocking probability. We examine three scenarios of increased complexity that gradually approximate real world settings. The obtained results show that the proposed framework leads to substantial performance improvements in terms of the aforementioned goals, when compared to current state of affairs.Comment: Accepted for Publication in IEEE Transactions on Smart Gri

Road user charging and implications for transport policy: Findings from the CURACAO project

This paper reports on the outcomes of a European project, CURACAO, designed to support the implementation of urban road user charging (URUC) as a demand management tool in urban areas. The project did this through engagement with a User Group of cities interested in pursuing URUC to identify the barriers preventing them from doing so. The project reviewed the complete process of setting up a URUC scheme from the setting of objectives, through to scheme design, predicting impacts, achieving acceptability and the implementation process and presented its findings in a State of the Art Report and a Case Studies Report. The State of the Art Report provides evidence collated from research and practice to address a series of 14 themes identified by the User Group, including objectives; scheme design; technology; business systems; prediction; traffic, environmental, economic and equity impacts; appraisal; acceptability; transferability; implementation; and evaluation. The Case Study Report reviewed 16 proposed or implemented schemes in Europe, focusing on pricing objectives, scheme design, the implementation process and scheme results. On this basis, the CURACAO Consortium developed a list of policy recommendations aimed at cities and regional authorities, national governments, and the European Commission. The paper summarises the main findings of the State of the Art Report and the case studies. On this basis, it outlines the policy recommendations which were drawn, and identifies future research needs

Markov Decision Processes with Applications in Wireless Sensor Networks: A Survey

Wireless sensor networks (WSNs) consist of autonomous and resource-limited devices. The devices cooperate to monitor one or more physical phenomena within an area of interest. WSNs operate as stochastic systems because of randomness in the monitored environments. For long service time and low maintenance cost, WSNs require adaptive and robust methods to address data exchange, topology formulation, resource and power optimization, sensing coverage and object detection, and security challenges. In these problems, sensor nodes are to make optimized decisions from a set of accessible strategies to achieve design goals. This survey reviews numerous applications of the Markov decision process (MDP) framework, a powerful decision-making tool to develop adaptive algorithms and protocols for WSNs. Furthermore, various solution methods are discussed and compared to serve as a guide for using MDPs in WSNs