Grid Interactive Charging/Discharging Strategy For Electric Vehicle Aggregators

With the fast development of electric vehicle (EV) industry, EVs have become one typical controllable resources on the demand side. The integration of large-scale EVs with random and uncertain characteristics will introduce a new challenge to the secure and economic operation of grid. To strengthen supply-demand interaction and create a win-win results, the charging load characteristic of EV cluster should be illustrated, the price and incentive method should be adopted to allocate EV load, charging/discharging strategy should be properly planned.Given this background, the pricing strategy and the charging/discharging strategy for EVs involved in EV-grid interaction subject are studied. Specifically, the main focuses of this dissertation can be summarized as follows:1) A generalized characteristics analysis of EV participating in demand response are presented from the following four parts, the aggregating charging load characteristics, operation mechanism, economic evaluation method, and a multi-agent based dispatch framework for EV-grid interaction.2) By the analysis of demand response reaction conducted by EV aggregator, EV load model under time-of-use price and zonal price is separately proposed, optimization model for time-of-use price and zonal price is separately presented to regulate the distribution of EV load temporally and spatially. The effect of EV demand response is evaluated by five quantitative index, satisfaction of power consumption way and power cost, load variation, peak-valley difference and power loss.3) Under a negotiated price based dispatch mode, a multi-period bidirectional charging/discharging optimization model for maximizing aggregator’s profit of frequency regulation was proposed to solve the problem of electric vehicle (EV) dispatches and its related battery wear cost evaluation. A heuristic prediction-correction algorithm was adopted to reduce evaluation error of battery wear costs. This method provide theoretical basis for scheduling strategy for EV (like private cars, public buses and taxies) aggregator participating in frequency regulation.