Due to the high penetration of renewable distributed generation(RDG),many issues have become conspicuous during the intentional island operation such as the power mismatch of load shedding during the transition proces...Due to the high penetration of renewable distributed generation(RDG),many issues have become conspicuous during the intentional island operation such as the power mismatch of load shedding during the transition process and the power imbalance during the restoration process.In this paper,a phase measurement unit(PMU)based online load shedding strategy and a conservation voltage reduction(CVR)based multi-period restoration strategy are proposed for the intentional island with RDG.The proposed load shedding strategy,which is driven by the blackout event,consists of the load shedding optimization and correction table.Before the occurrence of the large-scale blackout,the load shedding optimization is solved periodically to obtain the optimal load shedding plan,which meets the dynamic and steady constraints.When the blackout occurs,the correction table updated in real time based on the PMU data is used to modify the load shedding plan to eliminate the power mismatch caused by the fluctuation of RDG.After the system transits to the intentional island seamlessly,multi-period restoration plans are generated to optimize the restoration performance while maintaining power balance until the main grid is repaired.Besides,CVR technology is implemented to restore more loads by regulating load demand.The proposed load shedding optimization and restoration optimization are linearized to mixed-integer quadratic constraint programming(MIQCP)models.The effectiveness of the proposed strategies is verified with the modified IEEE 33-node system on the real-time digital simulation(RTDS)platform.展开更多
This research focuses on restructuring medium-level voltage(MLV)distribution systems by integrating distributed renewable energy resources(DER)at multiple feed points.It examines the impact of incorporating renewable ...This research focuses on restructuring medium-level voltage(MLV)distribution systems by integrating distributed renewable energy resources(DER)at multiple feed points.It examines the impact of incorporating renewable energy and evaluates system performance metrics such as robustness,static voltage stability,line carrying capacity,utility grid effectiveness,and losses within the conventional radial distribution framework commonly used in educational institutions.The contingency ranking of the real-time radial distribution system(RTRDS)for a typical educational institution consisting of N buses was conducted.Parameters such as the Voltage Performance Index(PIV)and Flow Performance Index(PIF)were evaluated.The results support the integration of distributed renewable energy sources within the existing radial distribution grid infrastructure.This research proposes enhanced contingency analyses through a straightforward reconfiguration process involving an additional tie line(Nþ1)for the existing N bus radial distribution system(RDS).Load flow analysis of the RDS with distributed renewable energy resources(DER)for both N bus and Nþ1 bus systems was conducted using the Gauss-Seidel and Newton–Raphson methods.Simulation results indicate that baseline loading is consistently maintained by grid sources and DER sources connected at multiple feed points.The proposed configuration of the Nþ1 bus system for the existing RTRDS was evaluated for voltage performance and compared with the Grey Wolf Optimization(GWO)algorithm.The results indicate that the Nþ1 bus configuration modeled using the MiPower tool performed comparably to the GWO results.Additionally,the contingency ranking for the proposed Nþ1 configuration was validated using the IEEE 10 and 30 bus system.展开更多
This study suggests an optimal renewable energy source(RES)allocation and distribution-static synchronous compensator(D-STATCOM)and passive power filters(PPFs)for an electrical distribution network(EDN)to improve its ...This study suggests an optimal renewable energy source(RES)allocation and distribution-static synchronous compensator(D-STATCOM)and passive power filters(PPFs)for an electrical distribution network(EDN)to improve its performance and power quality(PQ).First,the latest metaheuristic artificial rabbits optimization(ARO)is used to locate and size solar photovoltaic(PV),wind turbine(WT)and D-STATCOM units.In the second stage,ratings of single-tuned PPFs and D-STATCOMs at the RESs are determined,considering non-linear loads in the network.The multi-objective function reduces power loss,improves the voltage stability index(VSI)and limits total harmonic distortion.Simulations using the IEEE 33-bus EDN compared the ARO results with those of previous studies.In the first scenario,ideally integrated D-STATCOMs,PVs and WTs reduced losses by 34.79%,64.74%and 94.15%,respectively.VSI increases from 0.6965 to 0.7749,0.8804 and 0.967.The optimal WT integration of the first scenario outperformed the PVs and D-STATCOMs.The second step optimizes the WTs and PQ devices for non-linear loads.WTs and D-STATCOMs reduce the maximum total harmonic distortion of the voltage waveform by 5.21%with non-linear loads to 3.23%,while WTs and PPFs reduce it to 4.39%.These scenarios demonstrate how WTs and D-STATCOMs can improve network performance and PQ.The computational efficiency of ARO is compared to that of the pathfinder algorithm,future search algorithm,butterfly optimization algorithm and coyote optimization algorithm.ARO speeds up convergence and improves solution quality and comprehension.展开更多
基金This work was supported in part by the National Key R&D Program of China(No.2017YFB0902900)the National Natural Science Foundation of China(No.51707136)the Natural Science Foundation of Hubei Province(No.2018CFA080).
文摘Due to the high penetration of renewable distributed generation(RDG),many issues have become conspicuous during the intentional island operation such as the power mismatch of load shedding during the transition process and the power imbalance during the restoration process.In this paper,a phase measurement unit(PMU)based online load shedding strategy and a conservation voltage reduction(CVR)based multi-period restoration strategy are proposed for the intentional island with RDG.The proposed load shedding strategy,which is driven by the blackout event,consists of the load shedding optimization and correction table.Before the occurrence of the large-scale blackout,the load shedding optimization is solved periodically to obtain the optimal load shedding plan,which meets the dynamic and steady constraints.When the blackout occurs,the correction table updated in real time based on the PMU data is used to modify the load shedding plan to eliminate the power mismatch caused by the fluctuation of RDG.After the system transits to the intentional island seamlessly,multi-period restoration plans are generated to optimize the restoration performance while maintaining power balance until the main grid is repaired.Besides,CVR technology is implemented to restore more loads by regulating load demand.The proposed load shedding optimization and restoration optimization are linearized to mixed-integer quadratic constraint programming(MIQCP)models.The effectiveness of the proposed strategies is verified with the modified IEEE 33-node system on the real-time digital simulation(RTDS)platform.
文摘This research focuses on restructuring medium-level voltage(MLV)distribution systems by integrating distributed renewable energy resources(DER)at multiple feed points.It examines the impact of incorporating renewable energy and evaluates system performance metrics such as robustness,static voltage stability,line carrying capacity,utility grid effectiveness,and losses within the conventional radial distribution framework commonly used in educational institutions.The contingency ranking of the real-time radial distribution system(RTRDS)for a typical educational institution consisting of N buses was conducted.Parameters such as the Voltage Performance Index(PIV)and Flow Performance Index(PIF)were evaluated.The results support the integration of distributed renewable energy sources within the existing radial distribution grid infrastructure.This research proposes enhanced contingency analyses through a straightforward reconfiguration process involving an additional tie line(Nþ1)for the existing N bus radial distribution system(RDS).Load flow analysis of the RDS with distributed renewable energy resources(DER)for both N bus and Nþ1 bus systems was conducted using the Gauss-Seidel and Newton–Raphson methods.Simulation results indicate that baseline loading is consistently maintained by grid sources and DER sources connected at multiple feed points.The proposed configuration of the Nþ1 bus system for the existing RTRDS was evaluated for voltage performance and compared with the Grey Wolf Optimization(GWO)algorithm.The results indicate that the Nþ1 bus configuration modeled using the MiPower tool performed comparably to the GWO results.Additionally,the contingency ranking for the proposed Nþ1 configuration was validated using the IEEE 10 and 30 bus system.
文摘This study suggests an optimal renewable energy source(RES)allocation and distribution-static synchronous compensator(D-STATCOM)and passive power filters(PPFs)for an electrical distribution network(EDN)to improve its performance and power quality(PQ).First,the latest metaheuristic artificial rabbits optimization(ARO)is used to locate and size solar photovoltaic(PV),wind turbine(WT)and D-STATCOM units.In the second stage,ratings of single-tuned PPFs and D-STATCOMs at the RESs are determined,considering non-linear loads in the network.The multi-objective function reduces power loss,improves the voltage stability index(VSI)and limits total harmonic distortion.Simulations using the IEEE 33-bus EDN compared the ARO results with those of previous studies.In the first scenario,ideally integrated D-STATCOMs,PVs and WTs reduced losses by 34.79%,64.74%and 94.15%,respectively.VSI increases from 0.6965 to 0.7749,0.8804 and 0.967.The optimal WT integration of the first scenario outperformed the PVs and D-STATCOMs.The second step optimizes the WTs and PQ devices for non-linear loads.WTs and D-STATCOMs reduce the maximum total harmonic distortion of the voltage waveform by 5.21%with non-linear loads to 3.23%,while WTs and PPFs reduce it to 4.39%.These scenarios demonstrate how WTs and D-STATCOMs can improve network performance and PQ.The computational efficiency of ARO is compared to that of the pathfinder algorithm,future search algorithm,butterfly optimization algorithm and coyote optimization algorithm.ARO speeds up convergence and improves solution quality and comprehension.
