Reliability improvement considering plug-in hybrid electric vehicles parking lots ancillary services: a stochastic multi-criteria approach

In this study, the electric vehicle parking lot (PL) allocation problem is solved through considering PLs ancillary services in both reliability-related and operational programmes. The reliability-related objective function aims to simultaneously minimise the total reliability cost and system average interruption duration index. The total cost of reliability includes: total customer interruption cost, total cost of PL installation, and PL incorporation costs. PLs can provide two ancillary services in the restoration process, including: acting as a backup unit for the interrupted zone and as a storage unit in the backup feeder, to reduce the interruption duration and congestion occurrence, respectively. Moreover, a stochastic formulation is introduced for the reliability-based PL allocation to consider the uncertainties of restoration problem including: distribution system conditions and the available power of the participating PLs during restoration process. These uncertainties are realised through several restoration scenarios, which are derived based on historical data of outage occurrence and PLs tendency to participate in restoration process. Furthermore, energy loss and voltage deviation costs are considered in the operational objective function. Thus, both reliability-based and operational objectives are considered in the collective objective function to optimally benefit from different PLs ancillary services. A standard test system (RBTS-4) is employed to evaluate the effectiveness of the proposed approach.