Novel Multilevel Soft Constraints at Homes For Improving the Integration of Plug-in Electric Vehicles

High peak demand is one of the major problems induced by the penetration of a high number of Plug-in Electric Vehicles (PEVs) on the distribution system. Although time-varying electricity price, demand response, and incentive programs are suggested in many papers as solutions to smooth the peak-load, the results are not satisfactory. For example, in the presence of a dynamic price, all PEVs at homes tend to charge during periods when the electricity price is low. They may create peak demands that exceed the transformer power limit in unexpected periods when the power consumption is low. The situation gets worse when a fixed price is used in some countries and regions. PEVs tend to charge at any time without considering the presence or not of a peak load. To solve the problem of high penetration level of PEVs, we propose three novel contributions as follows, (i) a novel power Soft-Constraint at home level, (ii) a novel Multilevel Power-based Soft-Constraint, and (iii) a new Multilevel Power-based Electricity Tariff System are proposed. Simulation results show that our approach improves the integration of PEVs even when high penetration level is considered and even when fixed electricity price is used.