The first fully localized back-to-back DC intercon-nection project which connects Northwest and CentralChina power grids, 330-kV Lingbao Converter Stationhas now started construction for expansion.Lingbao back-to-back...The first fully localized back-to-back DC intercon-nection project which connects Northwest and CentralChina power grids, 330-kV Lingbao Converter Stationhas now started construction for expansion.Lingbao back-to-back converter station situated inLingbao City of Henan Province is the first DC intercon-展开更多
The filter capacitor stack is one of the main acoustic noise sources in high-voltage DC(HVDC) converter stations.As HVDC systems are built more and more recently,it is significant to research the audible noise of filt...The filter capacitor stack is one of the main acoustic noise sources in high-voltage DC(HVDC) converter stations.As HVDC systems are built more and more recently,it is significant to research the audible noise of filter capacitors.In this paper,the current situation of research on vibration and audible noise of filter capacitors in HVDC converter stations,which is departed into three parts—generation mechanism,prediction methods,and reduction measures,is presented and the research achievements are discussed.Scholars have built the model that the alternating electric force caused by the voltage conduces to the vibration,which propagates to the enclosure and radiates audible noise.As a result,the parts contributing most to the generation of audible noise are the top and the bottom of capacitors. In the noise level prediction respect,several methods have been prospected including impact hammer,sweep frequency, impact current,monopole and Kirchhoff formula method,which are suitable for single capacitors or capacitors stacks individually.However,the sweep frequency method is restricted by experiment condition,and the impact current method needs further research and verified.On the other hand,CIGRE WG14.26 provides three sound reduction measures,but all of them are not so practicable,while MPP absorber and compressible space absorber prospected by Dr.Wu Peng are proved to be effective.The sound barriers are also considered by scholars,and the acoustic directivity performance of capacitors is also researched.Besides,the developing direction of each research field is prospected in corresponding part.展开更多
The electromagnetic interference(EMI)from the valve hall as an important consideration in the design of high voltage direct current(HVDC)converter stations is analyzed by electromagnetic field numerical method and mea...The electromagnetic interference(EMI)from the valve hall as an important consideration in the design of high voltage direct current(HVDC)converter stations is analyzed by electromagnetic field numerical method and measurements.By using moment method,the EMI filed strength level as well as radio interference level(RIL)of the valve hall during the normal operation are computed after an antenna model is built for the valve tower.According to the character of EMI obtained,the practical shielding measures for valve hall are discussed to satisfy the relative standards.The test results for the500 kV converter station show that both the numerical method and shielding technique used in this paper are practical.展开更多
Subsequent commutation failure(SCF)can be easily generated during the first commutation failure(CF)recovery process in a line-commutated converter-based high voltage direct-current system.SCF poses a significant threa...Subsequent commutation failure(SCF)can be easily generated during the first commutation failure(CF)recovery process in a line-commutated converter-based high voltage direct-current system.SCF poses a significant threat to the safe and stable operation of power systems,and accurate prediction of CF is thus important.However,SCF is affected by the operating characteristics of the main circuit and the coupling effects of sequential control response in the inverter station.These are difficult to predict accurately.In this paper,a new SCF prediction method considering the control response is proposed based on the physical principle of SCF.The time sequence and switching conditions of the controllers at different stages of the first CF recovery process are described,and the corresponding equations of commutation voltage affected by different controllers are derived.The calculation method of the SCF threshold voltage is proposed,and the prediction method is established.Simulations show that the proposed method can predict SCF accurately and provide useful tools to suppress SCF.展开更多
Commutation failure(CF)is a frequent dynamic event at inverter of LCC-HVDC systems caused by AC side faults which can lead to inverter blocking,interruption of active power transfer,and even system blackout.To elimina...Commutation failure(CF)is a frequent dynamic event at inverter of LCC-HVDC systems caused by AC side faults which can lead to inverter blocking,interruption of active power transfer,and even system blackout.To eliminate CFs and improve system performance,new Flexible LCC-HVDC topologies have been proposed in previous research but with limited analysis on its economic performance.Therefore,to further validate the applicability of Flexible LCC-HVDC topologies,this paper utilizes Life-Cycle Cost Analysis model to analyze the life-cycle cost of inverter stations for conventional LCCHVDC,Capacitor Commutated Converter based HVDC(CCCHVDC)topology and Flexible LCC-HVDC topologies including Controllable Capacitor based Flexible LCC-HVDC,AC Filterless Controllable Capacitor based Flexible LCC-HVDC and improved Flexible LCC-HVDC.Through a case study based on a 500 kV,1000 MW LCC-HVDC scheme,comparison results show that the AC Filterless Controllable Capacitor based Flexible LCCHVDC topology and the improved Flexible LCC-HVDC topology have lower cost than the conventional LCC-HVDC and CCCHVDC topologies,which proves that the elimination of CFs can be achieved with reduced cost.展开更多
The overheating problems of terminal connectors severely threaten the operation of ultra-high voltage projects and cause enormous losses of economy,so a higher currentcarrying reliability of the connectors has an impo...The overheating problems of terminal connectors severely threaten the operation of ultra-high voltage projects and cause enormous losses of economy,so a higher currentcarrying reliability of the connectors has an important engineering significance with the development of transmission capacity.In this paper,a bivariate mathematical model of contact resistance as functions of temperature and tightening torque was deduced based on the large current temperature rise tests.To perform such analysis,four typical terminal connectors,namely:overlapping terminal of aluminum plates,overlapping terminal of copper plates,overlapping terminal of plates with clad layer and overlapping terminal of copper rod with aluminum clamp,were chosen for the experiments.The changing rules of DC resistance with different tightening torques and different currents were studied.Then the empirical formula of contact resistance was deduced.Finally,temperature calculations of different terminal connectors were realized to verify the effectiveness of the bivariate mathematical model.展开更多
文摘The first fully localized back-to-back DC intercon-nection project which connects Northwest and CentralChina power grids, 330-kV Lingbao Converter Stationhas now started construction for expansion.Lingbao back-to-back converter station situated inLingbao City of Henan Province is the first DC intercon-
基金Supported by National Natural Science Foundation of China(50907046)
文摘The filter capacitor stack is one of the main acoustic noise sources in high-voltage DC(HVDC) converter stations.As HVDC systems are built more and more recently,it is significant to research the audible noise of filter capacitors.In this paper,the current situation of research on vibration and audible noise of filter capacitors in HVDC converter stations,which is departed into three parts—generation mechanism,prediction methods,and reduction measures,is presented and the research achievements are discussed.Scholars have built the model that the alternating electric force caused by the voltage conduces to the vibration,which propagates to the enclosure and radiates audible noise.As a result,the parts contributing most to the generation of audible noise are the top and the bottom of capacitors. In the noise level prediction respect,several methods have been prospected including impact hammer,sweep frequency, impact current,monopole and Kirchhoff formula method,which are suitable for single capacitors or capacitors stacks individually.However,the sweep frequency method is restricted by experiment condition,and the impact current method needs further research and verified.On the other hand,CIGRE WG14.26 provides three sound reduction measures,but all of them are not so practicable,while MPP absorber and compressible space absorber prospected by Dr.Wu Peng are proved to be effective.The sound barriers are also considered by scholars,and the acoustic directivity performance of capacitors is also researched.Besides,the developing direction of each research field is prospected in corresponding part.
文摘The electromagnetic interference(EMI)from the valve hall as an important consideration in the design of high voltage direct current(HVDC)converter stations is analyzed by electromagnetic field numerical method and measurements.By using moment method,the EMI filed strength level as well as radio interference level(RIL)of the valve hall during the normal operation are computed after an antenna model is built for the valve tower.According to the character of EMI obtained,the practical shielding measures for valve hall are discussed to satisfy the relative standards.The test results for the500 kV converter station show that both the numerical method and shielding technique used in this paper are practical.
基金supported in part by the National Natural Science Foundation of China under Grant(51877018).
文摘Subsequent commutation failure(SCF)can be easily generated during the first commutation failure(CF)recovery process in a line-commutated converter-based high voltage direct-current system.SCF poses a significant threat to the safe and stable operation of power systems,and accurate prediction of CF is thus important.However,SCF is affected by the operating characteristics of the main circuit and the coupling effects of sequential control response in the inverter station.These are difficult to predict accurately.In this paper,a new SCF prediction method considering the control response is proposed based on the physical principle of SCF.The time sequence and switching conditions of the controllers at different stages of the first CF recovery process are described,and the corresponding equations of commutation voltage affected by different controllers are derived.The calculation method of the SCF threshold voltage is proposed,and the prediction method is established.Simulations show that the proposed method can predict SCF accurately and provide useful tools to suppress SCF.
基金supported by a collaborative project between the University of Birmingham and C-EPRI Electric Power Engineering Co.Ltd under grant“Key Technologies of Flexible LCC Converter with Controllable Capacitors”(SGNRPG00WZQT2100564A).
文摘Commutation failure(CF)is a frequent dynamic event at inverter of LCC-HVDC systems caused by AC side faults which can lead to inverter blocking,interruption of active power transfer,and even system blackout.To eliminate CFs and improve system performance,new Flexible LCC-HVDC topologies have been proposed in previous research but with limited analysis on its economic performance.Therefore,to further validate the applicability of Flexible LCC-HVDC topologies,this paper utilizes Life-Cycle Cost Analysis model to analyze the life-cycle cost of inverter stations for conventional LCCHVDC,Capacitor Commutated Converter based HVDC(CCCHVDC)topology and Flexible LCC-HVDC topologies including Controllable Capacitor based Flexible LCC-HVDC,AC Filterless Controllable Capacitor based Flexible LCC-HVDC and improved Flexible LCC-HVDC.Through a case study based on a 500 kV,1000 MW LCC-HVDC scheme,comparison results show that the AC Filterless Controllable Capacitor based Flexible LCCHVDC topology and the improved Flexible LCC-HVDC topology have lower cost than the conventional LCC-HVDC and CCCHVDC topologies,which proves that the elimination of CFs can be achieved with reduced cost.
基金This work was supported by the National Natural Science Foundation of China(51678548)the Science and Technology Project of the State Grid Corporation of China(GC71-16-003).
文摘The overheating problems of terminal connectors severely threaten the operation of ultra-high voltage projects and cause enormous losses of economy,so a higher currentcarrying reliability of the connectors has an important engineering significance with the development of transmission capacity.In this paper,a bivariate mathematical model of contact resistance as functions of temperature and tightening torque was deduced based on the large current temperature rise tests.To perform such analysis,four typical terminal connectors,namely:overlapping terminal of aluminum plates,overlapping terminal of copper plates,overlapping terminal of plates with clad layer and overlapping terminal of copper rod with aluminum clamp,were chosen for the experiments.The changing rules of DC resistance with different tightening torques and different currents were studied.Then the empirical formula of contact resistance was deduced.Finally,temperature calculations of different terminal connectors were realized to verify the effectiveness of the bivariate mathematical model.