摘要
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
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).