A Study Of Interruptible Load Participating In System Reserve

Interruptible load management is an important component of demand side managementin electricity market. With the progressive liberalization of the demand side, as avirtual-standby capacity and transmission capacity resources, IL is receiving more and moreattention in terms of peaking regulation and reducing the transmission congestion. In thebackground of energy shortages and serious environmental pollution, IL which is a resourceof demand side can interruptible burthen and substitute some electric generating sets toprovide reserve capacity. This would increase both systemic electricity generation and reservecapacity abundant, reduce the standby unit starting’s stopping and running costs, and thewaste of resources and emission of pollutants. At the same time, it would improve systemreliability, and increase the elasticity of demand and economic stability for users, which couldmake users enjoy higher-quality electricity services with the same price.As an important element of demand side management, interruptible load is permitted toparticipate in both energy market and reserve ancillary services bidding for power market inmany countries of the world. From the point of view that interruptible load could take part inthe system reserves, first of all, the paper introduced the system of reserve capacity in powermarket, which including the reserve capacity of generation side and interruptible load ofdemand side’s integrated configuration. Then, the concepts, contract contents, and theimplementations in different power markets at home and abroad of IL are presented. Finally,the costs and benefits of IL participating in system reserve are analyzed and summed in detail.And which also analyzed the benefits of implementing measure of IL’s from different views,which are independent system operator, power grid companies, power generation companiesand users of demand-side.As a supplemental resource of system reserve, interruptible loads can improve theeconomy of power system in the base of its reliability. Under the background ofenergy-saving and emission-reduction, the paper explained the differences between generatorunits and ILs in energy consumption and pollutant emission. By introducing the coefficient ofpollutant emission, taking minimized the total cost of reserve and pollutant emission as theobjective function, the paper has built the reserve assessment energy-savings and emissionsreduction scheduling model which could interruptible load participating for energy-savingpower generation with ILs considerations. At last it is solved by the genetic algorithm basedon hierarchical coding method. The results of calculation9-bus example system verified theeffectiveness of the model and algorithm. Optimal arrangement of resources between supply and demand sides, not only couldimprove the economy of power system, but also could reduce resources wasting andpollutants discharging, and then realizes the social benefits. Considered the cost of units’pollutants emission, an energy and reserve joint dispatch optimal power flow (OPF) model isproposed based on the idea that interruptible loads (ILs) could participate in system reserve.The power market total operational cost is studied when optimal system reserve capacity isdetermined with generator outages and ILs participates in system reserve. The results of anIEEE14-bus system show that the reserve cost is reduced and distribution of reserve capacityis optimized when system reserve capacity is determined with generator outages. It alsoshows that the total operational cost and pollutants emission cost are reduced, although thecost of the system reserve is improved.Finally, this paper has studied the temporary allocation price markup allocationmechanism for power price of high energy consumption customers during transitional periodand preliminary designed schemes of implementing interruptible loads in long-term situation,in connection with special cases of high energy consumption customers in Ya’an PowerCompany. Then a decision support system for small hydropower which designed formarketing apartment in Ya’an Power Company is briefly introduced.