Bi-level Economic Dispatch Model For Large Electricity Retailer

With the increasing liberalization of electricity,the electricity retailing market will be reformed more deeply.The retailing market will be open to social capitals.In a free and open retailing market,large retailers are faced with the risk of price fluctuation and uncertainty of load demand.And for most large retailers,it is necessary to own some kinds of distributed generations(DGs),controllable and uncontrollable ones.So it is a big challenge for large retailers to deal with the above uncertainties and achieve the most profitable electricity procurement and DG's scheduling strategies.A day-ahead bi-level optimal economic dispatch model for large electricity retailer is proposed:the upper-level model is devoted to maximizing social welfare so as to simulate joint optimization of energy and auxiliary service market,which can provide price information for retailers;the lower-level model is aimed at minimizing operation cost of electricity retailers,using chance-constrained theory to establish the optimal economic dispatch model,in which obtaining the purchase strategy and DG's scheduling strategy.Numerical results indicate that retailer owning controlled distributed generators can reduce the cost of electricity procurement,and eventually bring more benefit to retailer by reasonably dispatching these controlled DGs.And the increase of the confidence probability will cause the increase of the retailer's total cost,it is important for retailer to choose an appropriate value of confidence probability.The method we proposed can offer the science decision basis for large electricity retailers,and plays a positive role in promoting the policy of "retail side competition".