Charging of Electric Vehicle with Constant Price Using Photovoltaic Based Grid-connected System

Abstract

The charging of plug-in electric vehicle (PEV) imposes an additional burden on the utility grid, particularly during the (day) peak hours. This burden is normally controlled by shifting PEV charging to the grid off-peak hours. This shifting not only reduces the autonomy of anytime charging but also creates the uncertainty about the charging price every hour. To mitigate this problem, this paper proposes an energy management scheme (EMS) for the charging station that combines the photovoltaic (PV) and energy storage unit (ESU) with the grid. The models for PV power, ESU, PEV demand and grid electricity price are developed as the components of EMS. The scheme is capable of providing interruption-less charging during day-time. Moreover, the EMS has the capability to charge PEV with constant per unit price at and below the level of solar grid parity. The additional feature of EMS is that it can fulfill charging demand of each PEV within one hour at a lower price than standard grid (SG) charging while reducing the extra burden on the grid. The idea to reduce the economic loss of charging station due to cheaper and constant price charging is the involvement of valley-filling operation by both ESU and PEV along with selling the surplus PV energy to the grid. The EMS algorithm comprises of rule-based strategies. To determine the effectiveness of the scheme, numerous charging scenarios are simulated using Matlab. The initial results indicate that the charging through proposed scheme is much cheaper than the charging by conventional SG scheme. Moreover, it has shown to reduce the considerable amount of EV charging burden from the grid. It is envisaged that this is the first effort to propose constant price PEV charging and it will provide an exciting prospect in the field of PEV charging using renewable energy sources.