The introduction of fully controlled devices to build hybrid line commutated converter(H-LCC)has become a new idea to solve the commutation failure.However,existing H-LCC has not considered the implementation of a tar...The introduction of fully controlled devices to build hybrid line commutated converter(H-LCC)has become a new idea to solve the commutation failure.However,existing H-LCC has not considered the implementation of a targeted firing angle control strategy during AC faults,with the objective of enhancing their power transmission and fault response performance.For this reason,this paper proposes an optimized control method for firing angle of H-LCC,designated as flexible virtual firing(FVF).This method first analyzes the influence of alterations in firing angle on reactive power,commutation process and associated action paths.By combining prediction and dynamic search,it optimizes the natural commutation process through the utilization of dynamic boundary and minimum commutation area difference.This can mitigate the impact of AC faults on H-LCC and DC system,thereby improving power transmission and defense to commutation failure,which is beneficial for improving the stability of AC/DC power grids.Finally,the simulation results in PSCAD/EMTDC verify the effectiveness of the proposed method.展开更多
基金supported in part by the National Key Research and Development Program of China(No.2021YFB2400900)the Integration Projects of National Natural Science Foundation of China-State Grid Joint Fund for Smart Grid(No.U2166602)+1 种基金the National Natural Science Foundation of China(No.52207200)the Science and Technology Innovation Program of Hunan Province(No.2024RC3113).
文摘The introduction of fully controlled devices to build hybrid line commutated converter(H-LCC)has become a new idea to solve the commutation failure.However,existing H-LCC has not considered the implementation of a targeted firing angle control strategy during AC faults,with the objective of enhancing their power transmission and fault response performance.For this reason,this paper proposes an optimized control method for firing angle of H-LCC,designated as flexible virtual firing(FVF).This method first analyzes the influence of alterations in firing angle on reactive power,commutation process and associated action paths.By combining prediction and dynamic search,it optimizes the natural commutation process through the utilization of dynamic boundary and minimum commutation area difference.This can mitigate the impact of AC faults on H-LCC and DC system,thereby improving power transmission and defense to commutation failure,which is beneficial for improving the stability of AC/DC power grids.Finally,the simulation results in PSCAD/EMTDC verify the effectiveness of the proposed method.
