A Cloud-edge Cooperative Dispatching Method for Distribution Networks Considering Photovoltaic Generation Uncertainty

With the increasing penetration of renewable energy generation,uncertainty and randomness pose great challenges for optimal dispatching in distribution networks.We propose a cloud-edge cooperative dispatching(CECD)method to exploit the new opportunities offered by Internet of Things(IoT)technology.To alleviate the huge pressure on the modeling and computing of large-scale distribution system,the method deploys edge nodes in small-scale transformer areas in which robust optimization subproblem models are introduced to address the photovoltaic(PV)uncertainty.Considering the limited communication and computing capabilities of the edge nodes,the cloud center in the distribution automation system(DAS)establishes a utility grid master problem model that enforces the consistency between the solution at each edge node with the utility grid based on the alternating direction method of multipliers(ADMM).Furthermore,the voltage constraint derived from the linear power flow equations is adopted for enhancing the operation security of the distribution network.We perform a cloud-edge system simulation of the proposed CECD method and demonstrate a dispatching application.The case study is carried out on a modified 33-node system to verify the remarkable performance of the proposed model and method.

Cyber-attack Detection Strategy Based on Distribution System State Estimation

Cyber-attacks that tamper with measurement information threaten the security of state estimation for the current distribution system.This paper proposes a cyber-attack detection strategy based on distribution system state estimation(DSSE).The uncertainty of the distribution network is represented by the interval of each state variable.A three-phase interval DSSE model is proposed to construct the interval of each state variable.An improved iterative algorithm(IIA)is developed to solve the interval DSSE model and to obtain the lower and upper bounds of the interval.A cyber-attack is detected when the value of the state variable estimated by the traditional DSSE is out of the corresponding interval determined by the interval DSSE.To validate the proposed cyber-attack detection strategy,the basic principle of the cyber-attack is studied,and its general model is formulated.The proposed cyber-attack model and detection strategy are conducted on the IEEE 33-bus and 123-bus systems.Comparative experiments of the proposed IIA,Monte Carlo simulation algorithm,and interval Gauss elimination algorithm prove the validation of the proposed method.

Copper-Catalyzed [3 + 2 + 1] Cycloaddition of Alkenes with Benzoquinones and Dicarbonyl Compounds via Tandem Oxidative Dicarbofunctionalization/Cyclization Sequence

Developed is an efficient three-component [3 + 2 + 1] cycloaddition of simple alkenes with two C—H substrates via oxidative dicarbofunctionalization/cyclization sequence. The copper-catalyzed reaction involves the formation of two C—C bonds and one C—O bond through the cleavage of three C—H bonds in a single operation. The method has an excellent functional group tolerance, and features a broad substrate scope, affording a variety of functionalized chromenes in good yields.

Line Aging Assessment in Distribution Network Based on Topology Verification and Parameter Estimation

The aging of lines has a strong impact on the economy and safety of the distribution network.This paper proposes a novel approach to conduct line aging assessment in the distribution network based on topology verification and parameter estimation.In topology verification,the set of alternative topologies is firstly generated based on the switching lines.The best-matched topology is determined by comparing the difference between the actual measurement data and calculated voltage magnitude curves among the alternative topologies.Then,a novel parameter estimation approach is proposed to estimate the actual line parameters based on the measured active power,reactive power,and voltage magnitude data.It includes two stages,i.e.,the fixed-step aging parameter(FSAP)iteration,and specialized Newton-Raphson(SNR)iteration.The theoretical line parameters of the best-matched topology are taken as a warm start of FSAP,and the fitted result of FSAP is further renewed by the SNR.Based on the deviation between the renewed and theoretical line parameters,the aging severity risk level of each line is finally quantified through the risk assessment technology.Numerous experiments on the modified IEEE 33-bus and 123-bus systems demonstrate that the proposed approach can effectively conduct line aging assessment in the distribution network.