This paper presents a coordination strategy of Load Frequency Control(LFC)and digital frequency protection for an islanded microgrid(MG)considering high penetration of Renewable Energy Sources(RESs).In such MGs,the re...This paper presents a coordination strategy of Load Frequency Control(LFC)and digital frequency protection for an islanded microgrid(MG)considering high penetration of Renewable Energy Sources(RESs).In such MGs,the reduction in system inertia due to integration of large amount of RESs causes undesirable influence on MG frequency stability,leading to weakening of the MG.Furthermore,sudden load events,and short circuits caused large frequency fluctuations,which threaten the system security and could lead to complete blackouts as well as damages to the system equipment.Therefore,maintaining the dynamic security in MGs is one of the important challenges,which considered in this paper using a specific design and various data conversion stages of a digital over/under frequency relay(OUFR).The proposed relay will cover both under and over frequency conditions in coordination with LFC operation to protect the MG against high frequency variations.To prove the response of the proposed coordination strategy,a small MG was investigated for the simulation.The proposed coordination method has been tested considering load change,high integration of RESs.Moreover,the sensitivity analysis of the presented technique was examined by varying the penetration level of RESs and reducing the system inertia.The results reveal the effectiveness of the proposed coordination to maintain the power system frequency stability and security.In addition,the superiority of the OUFR has been approved in terms of accuracy and speed response during high disturbances.展开更多
With rapidly growing of Renewable Energy Sources(RESs)in renewable power systems,several disturbances influence on the power systems such as;lack of system inertia that results from replacing the synchronous generator...With rapidly growing of Renewable Energy Sources(RESs)in renewable power systems,several disturbances influence on the power systems such as;lack of system inertia that results from replacing the synchronous generators with RESs and frequency/voltage fluctuations that resulting from the intermittent nature of the RESs.Hence,the modern power systems become more susceptible to the system instability than conventional power systems.Therefore,in this study,a new application of Superconducting Magnetic Energy Storage(SMES)(i.e.,auxiliary Load Frequency Control(LFC))has been integrated with the secondary frequency control(i.e.,LFC)for frequency stability enhancement of the Egyptian Power System(EPS)due to high RESs penetration.Where,the coordinated control strategy is based on the PI controller that is optimally designed by the Particle Swarm Optimization(PSO)algorithm to minimize the frequency deviations of the EPS.The EPS includes both conventional generation units(i.e.,non-reheat,reheat and hydraulic power plants)with inherent nonlinearities,and RESs(i.e.,wind and solar energy).System modelling and simulation results are carried out using Matlab/Simulink^(■)software.The simulation results reveal the robustness of the proposed coordinated control strategy to preserve the system stability of the EPS with high penetration of RESs for different contingencies.展开更多
基金This paper is funded by the higher ministry of education in Egypt.
文摘This paper presents a coordination strategy of Load Frequency Control(LFC)and digital frequency protection for an islanded microgrid(MG)considering high penetration of Renewable Energy Sources(RESs).In such MGs,the reduction in system inertia due to integration of large amount of RESs causes undesirable influence on MG frequency stability,leading to weakening of the MG.Furthermore,sudden load events,and short circuits caused large frequency fluctuations,which threaten the system security and could lead to complete blackouts as well as damages to the system equipment.Therefore,maintaining the dynamic security in MGs is one of the important challenges,which considered in this paper using a specific design and various data conversion stages of a digital over/under frequency relay(OUFR).The proposed relay will cover both under and over frequency conditions in coordination with LFC operation to protect the MG against high frequency variations.To prove the response of the proposed coordination strategy,a small MG was investigated for the simulation.The proposed coordination method has been tested considering load change,high integration of RESs.Moreover,the sensitivity analysis of the presented technique was examined by varying the penetration level of RESs and reducing the system inertia.The results reveal the effectiveness of the proposed coordination to maintain the power system frequency stability and security.In addition,the superiority of the OUFR has been approved in terms of accuracy and speed response during high disturbances.
基金This paper was funded by the Cultural Affairs and Missions Sector of the Egyptian Ministry of Higher Education.
文摘With rapidly growing of Renewable Energy Sources(RESs)in renewable power systems,several disturbances influence on the power systems such as;lack of system inertia that results from replacing the synchronous generators with RESs and frequency/voltage fluctuations that resulting from the intermittent nature of the RESs.Hence,the modern power systems become more susceptible to the system instability than conventional power systems.Therefore,in this study,a new application of Superconducting Magnetic Energy Storage(SMES)(i.e.,auxiliary Load Frequency Control(LFC))has been integrated with the secondary frequency control(i.e.,LFC)for frequency stability enhancement of the Egyptian Power System(EPS)due to high RESs penetration.Where,the coordinated control strategy is based on the PI controller that is optimally designed by the Particle Swarm Optimization(PSO)algorithm to minimize the frequency deviations of the EPS.The EPS includes both conventional generation units(i.e.,non-reheat,reheat and hydraulic power plants)with inherent nonlinearities,and RESs(i.e.,wind and solar energy).System modelling and simulation results are carried out using Matlab/Simulink^(■)software.The simulation results reveal the robustness of the proposed coordinated control strategy to preserve the system stability of the EPS with high penetration of RESs for different contingencies.
