Bi-level Coordinated Planning of Active Distribution Network Considering Demand Response Resources and Severely Restricted Scenarios

Due to the uncertainty and fluctuation of distributed generation(DG)and load,the operation of active distribution network(ADN)is affected by multi-dimension factors which are described by massive operation scenarios.Efficient and accurate screening of severely restricted scenarios(SRSs)has become a new challenge in ADN planning.In this paper,a novel bi-level coordinated planning model which combines the short-time-scale operation problem with the long-time-scale planning problem is proposed.At the upper level,the demand response(DR)resource,an effective non-component planning resource characterized by low capacity price,high energy price,and short contract term,is co-optimized with the configuration of lines and energy storage systems(ESSs)to achieve the economic trade-off between the investment cost and the operation cost under SRSs.At the lower level,with the planning scheme obtained from the upper level,massive operation problems are optimized to minimize the daily operation cost;and the SRSs are provided to the upper level through a shadow-price-based scenario screening method,which simulates the planning information(i.e.,the restricted degrees of operation scenarios)feedback process from ADN operators to ADN planners.Case studies on a 62-node distribution system in Jianshan New District,Zhejiang Province,China,illustrate the effectiveness of the proposed bi-level coordinated planning model considering DR resources and SRSs.

End-of-life batteries management and material flow analysis in South Korea

Consumers increasingly have worn-out batteries as electrical and electronic equipment with new technical developments are introduced into the market and quickly replace older models. As a result, large amounts of end-of-life （EOL） or waste batteries are generated. Such batteries may contain a variety of materials that includes valuable resources as well as toxic elements. Thus, the proper recycling and management of batteries is very important from the perspective of resource conservation and environmental effect. The collection and recycling of EOL batteries is relatively low in South Korea compared to other countries, although an extended producer responsibility （EPR） policy was adopted for battery recycling in 2003. In this study, the management and material flow of EOL batteries is presented to determine potential problems and quantitative flow, based on literature review, site visits to battery recycling facilities, and interviews with experts in the Korea Battery Recycling Association （KBRA）, manufacturers, and regulators in government. The results show that approximately 558 tons of manganese-alkaline batteries, the largest fraction among recycling target items, was disposed in landfills or incinerators in 2015, while approximately 2,000 tons of batteries were recovered at a recycling facility by simple sorting and crushing processes. By raising environmental awareness, more diverse and effective collection systems could be established for consumers to easily dispose of EOL batteries in many places. Producers, retailers and distributors in South Korea should also play an important role in the collection of EOL batteries from consumers. Lithium-ion batteries from many electronic devices must be included in the EPR system for resource recovery.