Offshore wind farms(OWFs)have received widespread attention for their abundant unexploited wind energy poten-tial and convenient locations conditions.They are rapidly developing towards having large capacity and being...Offshore wind farms(OWFs)have received widespread attention for their abundant unexploited wind energy poten-tial and convenient locations conditions.They are rapidly developing towards having large capacity and being located further away from shore.It is thus necessary to explore effective power transmission technologies to connect large OWFs to onshore grids.At present,three types of power transmission technologies have been proposed for large OWF integration.They are:high voltage alternating current(HVAC)transmission,high voltage direct current(HVDC)transmission,and low-frequency alternating current(LFAC)or fractional frequency alternating current transmission.This work undertakes a comprehensive review of grid connection technologies for large OWF integration.Compared with previous reviews,a more exhaustive summary is provided to elaborate HVAC,LFAC,and five HVDC topologies,consisting of line-commutated converter HVDC,voltage source converter HVDC,hybrid-HVDC,diode rectifier-based HVDC,and all DC transmission systems.The fault ride-through technologies of the grid connection schemes are also presented in detail to provide research references and guidelines for researchers.In addition,a comprehensive evalu-ation of the seven grid connection technologies for large OWFs is proposed based on eight specific indicators.Finally,eight conclusions and six perspectives are outlined for future research in integrating large OWFs.展开更多
A review of the electrical collection systems in offshore wind farms(OWFs)is presented in this paper.The review is based on a categorization of offshore wind power electrical collection systems.The classification enco...A review of the electrical collection systems in offshore wind farms(OWFs)is presented in this paper.The review is based on a categorization of offshore wind power electrical collection systems.The classification encompasses three categories of electrical collection systems,medium voltage AC collection,medium voltage DC collection systems and low frequency AC collection systems(LFAC).This paper summarizes the related research on different collection systems and explores their operational characteristics and challenges.As the initial cost of an OWF is very much influenced,to a great extent,by the configuration of electrical collection and transmission systems,it is necessary to understand the key components and challenges in each collection system configuration.展开更多
For a cost-effective connection of large-scale longdistance wind energy,a low frequency alternating current(LFAC)transmission scheme(16.7 Hz or 20 Hz)is proposed as an alternative to the conventional high voltage alte...For a cost-effective connection of large-scale longdistance wind energy,a low frequency alternating current(LFAC)transmission scheme(16.7 Hz or 20 Hz)is proposed as an alternative to the conventional high voltage alternating current(HVAC)transmission scheme(50 Hz or 60 Hz)and the recently popular high voltage direct current(HVDC)transmission scheme(0 Hz).The technical feasibility of the LFAC system is demonstrated but the basis for identifying the distance ranges for which LFAC would be preferable to HVAC and HVDC are not established and the dependence of this range on factors,such as power transfer rating,voltage rating and cable/line type,is not investigated.This paper presents an in-depth analysis for the overall cost of LFAC system and then provides an extensive comparison with HVAC and HVDC,to explore the distance ranges over which LFAC is cost-effective over both HVAC and HVDC in connections of offshore and remote onshore wind energy.The results demonstrate that the LFAC system does possess ranges in the intermediate distance for which it is more cost-effective than both HVAC and HVDC,and its overall cost advantage is generally larger in the overhead line(OHL)connection of remote onshore wind energy than the cable connection of offshore wind energy.展开更多
基金National Natural Science Foundation of China (61963020)National Natural Science Foundation of China (52022035)+2 种基金Key Program of National Natural Science Foundation of China (52037003)Major Special Project of Yunnan Province of China (202002AF080001)Curriculum ideological and political connotation construction project (2021KS037).
文摘Offshore wind farms(OWFs)have received widespread attention for their abundant unexploited wind energy poten-tial and convenient locations conditions.They are rapidly developing towards having large capacity and being located further away from shore.It is thus necessary to explore effective power transmission technologies to connect large OWFs to onshore grids.At present,three types of power transmission technologies have been proposed for large OWF integration.They are:high voltage alternating current(HVAC)transmission,high voltage direct current(HVDC)transmission,and low-frequency alternating current(LFAC)or fractional frequency alternating current transmission.This work undertakes a comprehensive review of grid connection technologies for large OWF integration.Compared with previous reviews,a more exhaustive summary is provided to elaborate HVAC,LFAC,and five HVDC topologies,consisting of line-commutated converter HVDC,voltage source converter HVDC,hybrid-HVDC,diode rectifier-based HVDC,and all DC transmission systems.The fault ride-through technologies of the grid connection schemes are also presented in detail to provide research references and guidelines for researchers.In addition,a comprehensive evalu-ation of the seven grid connection technologies for large OWFs is proposed based on eight specific indicators.Finally,eight conclusions and six perspectives are outlined for future research in integrating large OWFs.
文摘A review of the electrical collection systems in offshore wind farms(OWFs)is presented in this paper.The review is based on a categorization of offshore wind power electrical collection systems.The classification encompasses three categories of electrical collection systems,medium voltage AC collection,medium voltage DC collection systems and low frequency AC collection systems(LFAC).This paper summarizes the related research on different collection systems and explores their operational characteristics and challenges.As the initial cost of an OWF is very much influenced,to a great extent,by the configuration of electrical collection and transmission systems,it is necessary to understand the key components and challenges in each collection system configuration.
基金supported by the National Natural Science Foundation of China(51925702,52107214)China-UK NSFC-EPSRC Joint Project(52061635101,EP/T021780/1).
文摘For a cost-effective connection of large-scale longdistance wind energy,a low frequency alternating current(LFAC)transmission scheme(16.7 Hz or 20 Hz)is proposed as an alternative to the conventional high voltage alternating current(HVAC)transmission scheme(50 Hz or 60 Hz)and the recently popular high voltage direct current(HVDC)transmission scheme(0 Hz).The technical feasibility of the LFAC system is demonstrated but the basis for identifying the distance ranges for which LFAC would be preferable to HVAC and HVDC are not established and the dependence of this range on factors,such as power transfer rating,voltage rating and cable/line type,is not investigated.This paper presents an in-depth analysis for the overall cost of LFAC system and then provides an extensive comparison with HVAC and HVDC,to explore the distance ranges over which LFAC is cost-effective over both HVAC and HVDC in connections of offshore and remote onshore wind energy.The results demonstrate that the LFAC system does possess ranges in the intermediate distance for which it is more cost-effective than both HVAC and HVDC,and its overall cost advantage is generally larger in the overhead line(OHL)connection of remote onshore wind energy than the cable connection of offshore wind energy.
