Shijiazhuang’s Electric Peower System Planning Based On Fuzzy-queue Theory

In recent years,with the development of economy,society and technology as well as population growth,the demand for electricity in China has been increasing.And electric power supply of China has been mainly relied on coal-fired power generation all the time.However,coal resources distribution is geographically inhomogenous.In the area with the shortage of coal resources,there are numbers of factors on coal purchase and transportation,thus bringing about uncertainties.In addition,uncertainties exist in electric power system with changing prices and demands of electricity.Thus,electric power system planning plays an increasing important part.In this study,a fuzzy-queue based interval programming(FQIP)method is developed for planning electric power systems(EPS)under uncertainty.Through incorporating interval-parameter programming(IPP),fuzzy programming(FP)and queue theory within a general framework,FQIP can not only deal with uncertainties expressed as interval values and fuzzy sets,but also is useful for studying the behavior of dynamic service delivery systems.With the consideration of the coal shortage and the queuing problem of coal purchase process in Shijiazhuang,the electric power system planning model based on FQIP(FQIP-EPS)is developed.The FQIP-EPS model is used to investigate the effects of M/M/1 queues with fuzzy information and different storage periods on the EPS.The coal purchase schemes,power generation plans,pollutant emissions as well as costs of each part under different degrees of membership can be obtained through FQIP-EPS model.Results indicate that:a higher waiting time corresponds to a larger amount of coal with lower calorific value purchased nearby,thus resulting in higher purchase and system costs;with the decreasing of storage periods,coal purchase batches would increase which could lead to a increased waiting time and a raised system cost;the increasing of storage periods would decrease the PM and NOx emissions of per unit electricity;less waiting time and longer storage period would be beneficial for the optimization of Shijiazhuang’s EPS.The results are helpful for decision makers to make appropriate coal purchase and electricity generation plans,as well as gain insight into the effects of queuing problem and storage period on EPS under uncertainties.