This paper presents an Multi-Input Multi-Output(MIMO)analysis to investigate the mutual interactions and small-signal stability of bipolar-type dc microgrids.Since bipolar dc microgrid is replete with power-electronic...This paper presents an Multi-Input Multi-Output(MIMO)analysis to investigate the mutual interactions and small-signal stability of bipolar-type dc microgrids.Since bipolar dc microgrid is replete with power-electronic converters,its dynamics can not be understood unless the interactions among control systems of converters are properly investigated.To tackle the challenge,each converter in microgrid is modeled via an MIMO transfer matrix.Then,the MIMO models are combined together based on the interactions among the control systems of source and load converters.From this integrative MIMO model,the mutual interactions between various input-output pairs are quantified using Gershgorin Band theorem.Also,Singular Value Decomposition(SVD)analysis is carried out to estimate the frequency of unstable poles.Test results not only successfully validate the effectiveness of the MIMO method but also show that the control system of voltage balancer has a major impact on the overall stability of bipolar dc microgrid,making it a suitable location for applying damping systems.展开更多
Considering the majority of electrical equipment utilized in society is driven by DC,integrating a DC system can significantly enhance the efficiency and reliability of power sys-tems by implementing the integration o...Considering the majority of electrical equipment utilized in society is driven by DC,integrating a DC system can significantly enhance the efficiency and reliability of power sys-tems by implementing the integration of diverse loads,renew-able energy sources(RESs),and energy storage systems(ESSs).In this paper,the integration of multiple DC zero-carbon build-ings(DC-ZCBs)is proposed to achieve the unbalanced voltage suppression of the bipolar DC microgrid(DCMG).The photo-voltaic(PV)technology,loads,and DC electric springs(DC-ESs)are adopted as a unified entity to achieve the zero-carbon emission of the building.Firstly,a new configuration of PV and DC-ESs is introduced.The energy management of PV,ESS,and load are fully considered in this new configuration,which can reduce the capacity of the EsS.Subsequently,a distributed co-operative control strategy for DC-ESs based on the modulus voltage is presented,which is implemented with integration of the new configuration into the bipolar DCMG.The proposed approach addresses the issues of unbalanced voltage to improve the operating efficiency and power quality of the bipolar DC-MG.The simulation is conducted in MATLAB/Simulink plat-form to confirm the effectiveness of the proposed approach.展开更多
针对偏远地区电力资源缺乏且风能充足的特点,设计了一种孤岛运行的小型风储直流微网系统。该系统采用双极性直流母线结构,降低了母线对地电压,同时满足各种变换器和负荷对不同电压等级的要求,使系统更加安全可靠。利用电压平衡器保证了...针对偏远地区电力资源缺乏且风能充足的特点,设计了一种孤岛运行的小型风储直流微网系统。该系统采用双极性直流母线结构,降低了母线对地电压,同时满足各种变换器和负荷对不同电压等级的要求,使系统更加安全可靠。利用电压平衡器保证了正负母线电压平衡,并分别设计了风力发电单元和混合储能单元(hybrid energy storage system,HESS)在不同工况下的最优工作方式。将该小型风储直流微网系统运行分为五种模式,通过对风机、混合储能以及负荷进行协调控制,确保直流母线电压的稳定和负荷的可靠供电。最后通过仿真验证了系统运行的稳定性和控制策略的可行性。展开更多
基金This work was supported by the U.S.National Science Foundation under Grant Nos.1647209 and 1611095the European Unions Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant No.765585.
文摘This paper presents an Multi-Input Multi-Output(MIMO)analysis to investigate the mutual interactions and small-signal stability of bipolar-type dc microgrids.Since bipolar dc microgrid is replete with power-electronic converters,its dynamics can not be understood unless the interactions among control systems of converters are properly investigated.To tackle the challenge,each converter in microgrid is modeled via an MIMO transfer matrix.Then,the MIMO models are combined together based on the interactions among the control systems of source and load converters.From this integrative MIMO model,the mutual interactions between various input-output pairs are quantified using Gershgorin Band theorem.Also,Singular Value Decomposition(SVD)analysis is carried out to estimate the frequency of unstable poles.Test results not only successfully validate the effectiveness of the MIMO method but also show that the control system of voltage balancer has a major impact on the overall stability of bipolar dc microgrid,making it a suitable location for applying damping systems.
基金This work was supported by the National Natural Science Foundation of China(No.52077017).
文摘Considering the majority of electrical equipment utilized in society is driven by DC,integrating a DC system can significantly enhance the efficiency and reliability of power sys-tems by implementing the integration of diverse loads,renew-able energy sources(RESs),and energy storage systems(ESSs).In this paper,the integration of multiple DC zero-carbon build-ings(DC-ZCBs)is proposed to achieve the unbalanced voltage suppression of the bipolar DC microgrid(DCMG).The photo-voltaic(PV)technology,loads,and DC electric springs(DC-ESs)are adopted as a unified entity to achieve the zero-carbon emission of the building.Firstly,a new configuration of PV and DC-ESs is introduced.The energy management of PV,ESS,and load are fully considered in this new configuration,which can reduce the capacity of the EsS.Subsequently,a distributed co-operative control strategy for DC-ESs based on the modulus voltage is presented,which is implemented with integration of the new configuration into the bipolar DCMG.The proposed approach addresses the issues of unbalanced voltage to improve the operating efficiency and power quality of the bipolar DC-MG.The simulation is conducted in MATLAB/Simulink plat-form to confirm the effectiveness of the proposed approach.
文摘针对偏远地区电力资源缺乏且风能充足的特点,设计了一种孤岛运行的小型风储直流微网系统。该系统采用双极性直流母线结构,降低了母线对地电压,同时满足各种变换器和负荷对不同电压等级的要求,使系统更加安全可靠。利用电压平衡器保证了正负母线电压平衡,并分别设计了风力发电单元和混合储能单元(hybrid energy storage system,HESS)在不同工况下的最优工作方式。将该小型风储直流微网系统运行分为五种模式,通过对风机、混合储能以及负荷进行协调控制,确保直流母线电压的稳定和负荷的可靠供电。最后通过仿真验证了系统运行的稳定性和控制策略的可行性。
