大规模光伏电站孤岛经柔性直流送出的电压特性OA北大核心CSTPCD

For the power transmission of photovoltaic base of the desert and gobi area,it is an important technical solution that the islanded PV station is transmitted via voltage source convert based high voltage direct current(VSC-HVDC).However,VSC-HVDC device is the only steady-state AC voltage source instead of the traditional rotational equipment,which will result in the system volt-age characteristics being different from that of the traditional power grid.Therefore,the researches on the steady-state and transient voltage characteristics of the large-scale islanded PV station transmitted via VSC-HVDC are conducted.Firstly,the system of the large-scale PV station transmitted via VSC-HVDC is introduced in detail.Secondly,the analysis model of steady-state voltage of the islanded transmission system is built,and a steady-state voltage characteristic and power limit analysis method using power circle as a representation and VSC-HVDC transient and steady-state reactive power capacity is proposed,and the steady-state voltage characteristic analysis is carried out through a numerical example system.After that,the transient voltage characteristics of large-scale islanded photovoltaic power plants under severe AC faults in the VSC-HVDC island transmission system are studied,and a new energy and VSC-HVDC transient coordinated control strategy is proposeded.Finally,measures are proposed to improve voltage stability and transient characteristics,which can provide reference for the actual operation design of photovoltaic power plant island VSC-HVDC transmission systems.