In recent years,the penetration of renewable resources into AC power systems has increased tremendously,creating a significantly impact on the latter’s operations and stability.In this respect,it is also important to...In recent years,the penetration of renewable resources into AC power systems has increased tremendously,creating a significantly impact on the latter’s operations and stability.In this respect,it is also important to gain a basic analytical understanding of such impact on the steady-state stability of power systems with electrically weak AC/DC interconnections,but such works are not very evident in the literature.Therefore,a classical analytic model of the single and multi-infeed HVDC system which now incorporates renewable resources is proposed.Then the well-established concept of voltage sensitivity of the AC/DC interconnection is applied to analyze the impact of the renewable resources on the steady-state stability of these composite system models,as well as on the influence of system conditions and parameters.This impact is also compared with that arising from other types of shunt devices alternatively connected at the same AC/DC interconnection,therefore their relative beneficial or negative impacts will also be benchmarked.展开更多
In view of the reactive power coordination difficulties caused by reactive power strong coupling,the provincial power grids in the interconnected system are formed by the multi-AC/DC transmission.Wind power channels a...In view of the reactive power coordination difficulties caused by reactive power strong coupling,the provincial power grids in the interconnected system are formed by the multi-AC/DC transmission.Wind power channels are under the conditions of large-scale long-distance transmission of wind power and other forms of renewable power generation.The AC-DC hybrid power flow equation of the interconnected system,including the AC-DC tie lines,is presented in this paper,along with the robust dynamic evolutionary optimization of the reactive power system in interconnected systems under fluctuating and uncertain wind power conditions.Therefore,the rapid collaborative optimization of reactive power flow and the exchange of reactive power between tie lines between provincial power grids are realized.The analysis was made by taking four interconnected large-scale provincial power grids of Eastern Mongolia,Jilin,Liaoning and Shandong as an example.The simulation results demonstrate the effectiveness and superiority of the proposed reactive power dynamic multi-objective optimization method for interconnected power grids.展开更多
This paper examines the interconnection of two DC microgrids(MGs) with tie-line. The voltages at respective MG buses are controlled to manage the powerflow across the tie-line. Formation of such a DC MG cluster ensure...This paper examines the interconnection of two DC microgrids(MGs) with tie-line. The voltages at respective MG buses are controlled to manage the powerflow across the tie-line. Formation of such a DC MG cluster ensures higher reliability of power supply andflexibility to manage distributed energy resources and loads in the system. Two MGs consist of photovoltaic and battery units interfaced by power electronic converters. The bus voltages of two DC MGs act as an indicator for the powerflow monitoring the supply-demand balance. A decentralized control approach is proposed to control each MG and bus voltage fluctuation in an allowable range. Furthermore,a mode adaptive decentralized control approach is proposed for seamless mode transition in order to assign microgrid operation modes and for the power management of DC MGs. The effectiveness of the proposed concept is validated by simulation and experimental results.展开更多
文摘In recent years,the penetration of renewable resources into AC power systems has increased tremendously,creating a significantly impact on the latter’s operations and stability.In this respect,it is also important to gain a basic analytical understanding of such impact on the steady-state stability of power systems with electrically weak AC/DC interconnections,but such works are not very evident in the literature.Therefore,a classical analytic model of the single and multi-infeed HVDC system which now incorporates renewable resources is proposed.Then the well-established concept of voltage sensitivity of the AC/DC interconnection is applied to analyze the impact of the renewable resources on the steady-state stability of these composite system models,as well as on the influence of system conditions and parameters.This impact is also compared with that arising from other types of shunt devices alternatively connected at the same AC/DC interconnection,therefore their relative beneficial or negative impacts will also be benchmarked.
基金This work was supported by the National Key Research and Development Program of China under Grant No.2017YFB0902100.
文摘In view of the reactive power coordination difficulties caused by reactive power strong coupling,the provincial power grids in the interconnected system are formed by the multi-AC/DC transmission.Wind power channels are under the conditions of large-scale long-distance transmission of wind power and other forms of renewable power generation.The AC-DC hybrid power flow equation of the interconnected system,including the AC-DC tie lines,is presented in this paper,along with the robust dynamic evolutionary optimization of the reactive power system in interconnected systems under fluctuating and uncertain wind power conditions.Therefore,the rapid collaborative optimization of reactive power flow and the exchange of reactive power between tie lines between provincial power grids are realized.The analysis was made by taking four interconnected large-scale provincial power grids of Eastern Mongolia,Jilin,Liaoning and Shandong as an example.The simulation results demonstrate the effectiveness and superiority of the proposed reactive power dynamic multi-objective optimization method for interconnected power grids.
文摘This paper examines the interconnection of two DC microgrids(MGs) with tie-line. The voltages at respective MG buses are controlled to manage the powerflow across the tie-line. Formation of such a DC MG cluster ensures higher reliability of power supply andflexibility to manage distributed energy resources and loads in the system. Two MGs consist of photovoltaic and battery units interfaced by power electronic converters. The bus voltages of two DC MGs act as an indicator for the powerflow monitoring the supply-demand balance. A decentralized control approach is proposed to control each MG and bus voltage fluctuation in an allowable range. Furthermore,a mode adaptive decentralized control approach is proposed for seamless mode transition in order to assign microgrid operation modes and for the power management of DC MGs. The effectiveness of the proposed concept is validated by simulation and experimental results.
