PEV charging coordination to absorb excess wind energy via group differentiated dual-tariff schemes

Abstract Curtailment of wind energy in off-peak periods has gradually concerned the electric power industry. This paper aims to coordinate charging behaviors of plug-in electric vehicles (PEVs) for absorbing the excess wind energy. A long-term wind-to-vehicle (W2V) coordination program is proposed via novel dual-tariff (two-stage time-of-use tariff, i.e., ordinary tariff and cheap tariff) schemes. Unlike consensus time-of-use tariff scheme applying identical cheap-tariff time to all individual PEVs, the novel schemes artfully stagger their cheap-tariff times for different PEV-groups, thereby differentiating themselves among PEV-groups. Novel schemes use their execution probabilities to help allocate PEVs into different PEV-groups. PEVs in the same low voltage (LV) feeder will be spread into different PEV-groups rather than clustering into one PEV-group, by which PEVs to be charged in each PEV-group will be distributed across the entire distribution networks. Hence, the synergy between PEV’s charging load and wind power generation is greatly enhanced and the undesirable charging synchrony is much alleviated. To this end, a local charging coordination method is proposed at the charging device level, by which an original analytical model is developed for the calculation of aggregated charging load (ACL) at the transmission system level. Based on the coordinated ACL model, an optimization problem is formulated to help design the novel dual-tariff schemes. A heuristic algorithm is proposed to solve the optimization problem. Numerical results prove the effectiveness of the heuristic algorithm, and extensive tests show high performances of the W2V coordination program.