As the integration of distributed generations(DGs)transforms the traditional distribution network into the active distribution network,voltage stability assessments(VSA)of transmission grid and distribution grid are n...As the integration of distributed generations(DGs)transforms the traditional distribution network into the active distribution network,voltage stability assessments(VSA)of transmission grid and distribution grid are not suitable to be studied separately.This paper presents a distributed continuation power flow method for VSA of global transmission and distribution grid.Two different parameterization schemes are adopted to guarantee the coherence of load growth in transmission and distribution grids.In the correction step,the boundary bus voltage,load parameter and equivalent power are communicated between the transmission and distribution control centers to realize the distributed computation of load margin.The optimal multiplier technique is used to improve the convergence of the proposed method.The three-phase unbalanced characteristic of distribution networks and the reactive capability limits of DGs are considered.Simulation results on two integrated transmission and distribution test systems show that the proposed method is effective.展开更多
The multi-voltage-level DC distribution network(MVL-DC-DN)is a promising network for efficiently integrat ing rapidly growing DC loads,and fast-growing load demand would bring a challenge to the MVL-DC-DN in terms of ...The multi-voltage-level DC distribution network(MVL-DC-DN)is a promising network for efficiently integrat ing rapidly growing DC loads,and fast-growing load demand would bring a challenge to the MVL-DC-DN in terms of the maximum loadability.This paper considers the DC electric spring(DC-ES)as a novel candidate flexible resource for en hancing the maximum loadability of the MVL-DC-DN,and pro poses an evaluation method for the maximum loadability.First ly,with the consideration of device constraints,the impact that the DC-ES on the maximum loadability of the DC distribution network(DC-DN)is analyzed via a simplified equivalent cir cuit.Subsequently,the power flow(PF)model of an MVL-DCDN with DC-ESs is established.Finally,a method based on con tinuation power flow(CPF)for evaluating the maximum load ability of an MVL-DC-DN with DC-ESs is proposed.During the evaluation,limitations of the DC-ES and the DC transform er(DCT)are considered.The consideration of the practical con straints avoids the overestimation of the maximum loadability.The case study verifies the effectiveness of the proposed method.展开更多
基金This work is supported by National Natural Science Foundation of China(No.51077042,No.51577049)Special Foundation of The doctoral program of Higher Education(No.20120094110008).
文摘As the integration of distributed generations(DGs)transforms the traditional distribution network into the active distribution network,voltage stability assessments(VSA)of transmission grid and distribution grid are not suitable to be studied separately.This paper presents a distributed continuation power flow method for VSA of global transmission and distribution grid.Two different parameterization schemes are adopted to guarantee the coherence of load growth in transmission and distribution grids.In the correction step,the boundary bus voltage,load parameter and equivalent power are communicated between the transmission and distribution control centers to realize the distributed computation of load margin.The optimal multiplier technique is used to improve the convergence of the proposed method.The three-phase unbalanced characteristic of distribution networks and the reactive capability limits of DGs are considered.Simulation results on two integrated transmission and distribution test systems show that the proposed method is effective.
基金supported in part by the National Natural Science Foundation of China(No.52077017).
文摘The multi-voltage-level DC distribution network(MVL-DC-DN)is a promising network for efficiently integrat ing rapidly growing DC loads,and fast-growing load demand would bring a challenge to the MVL-DC-DN in terms of the maximum loadability.This paper considers the DC electric spring(DC-ES)as a novel candidate flexible resource for en hancing the maximum loadability of the MVL-DC-DN,and pro poses an evaluation method for the maximum loadability.First ly,with the consideration of device constraints,the impact that the DC-ES on the maximum loadability of the DC distribution network(DC-DN)is analyzed via a simplified equivalent cir cuit.Subsequently,the power flow(PF)model of an MVL-DCDN with DC-ESs is established.Finally,a method based on con tinuation power flow(CPF)for evaluating the maximum load ability of an MVL-DC-DN with DC-ESs is proposed.During the evaluation,limitations of the DC-ES and the DC transform er(DCT)are considered.The consideration of the practical con straints avoids the overestimation of the maximum loadability.The case study verifies the effectiveness of the proposed method.
