光伏接入直流受端电网下直流换相失败影响机理初探OA北大核心CSTPCD

With the promotion of the"carbon peaking and carbon neutrality"goals,many renewable energy power generation systems will be connected to the receiving grid of the high voltage direct current(HVDC)transmission system.However,few studies have covered this research scenario,and whether renewable energy will adversely affect DC operations is doubtful.For this reason,this paper analyzes the output characteristics and interactive influence rules of photovoltaic and HVDC under AC power grid faults.It is found that positive and negative sequence current components of 50,100,and 150Hz will be transmitted to the photovoltaic system after HVDC commutation failure,resulting in fluctuations of photovoltaic output power and voltage of connecting points.The feedback transmission of the receiving grid leads to the fluctuation of the HVDC current and the advance trigger angle order of the HVDC system,thus bringing the risk of HVDC subsequent commutation failure.Finally,combined with the PSCAD/EMTDC simulation software,the high-voltage DC transmission system model of the receiving grid with photovoltaic access is built,and the rationality and validity of the above conclusions are verified by simulation.