高比例新能源送端系统暂态电压运行风险分析OACSTPCD

The transient voltage evolution and propagation and operational risk of a high-proportion new energy sending system in AC/DC faults are unclear.Thus,first,based on an analysis of the reactive voltage interaction mechanism between AC and DC systems,the characteristics and dominant influencing factors of transient voltage in AC and DC faults are identified,and the transient voltage evolution propagation path dominated by power electronic equipment in such a system is clarified.Second,the transient voltage operational risk is systematically considered from three aspects:the strong coupling effect of AC and DC faults continuing to strengthen,and the transient reactive power component is complex;the proportion of new energy continuing to increase,and the transient voltage problem becomes prominent;the tolerance for fault and adjustment ability decreases,and the risk of new energy tripping increases.Then,based on the DIgSILENT/PowerFactory,a simulation model of an actual high-proportion new energy multi-HVDC transmission system is established.The results with different new energy ratios and fault conditions verify the correctness of the transient voltage operational risk analysis.Finally,the technical prospect of coping with the operational risk of transient voltage is examined from the aspects of enhancing the mechanism understanding of coupling operational characteristics,improving the performance of a new energy-related grid,increasing the ability of multi-scale cooperative control strategy,and strengthening the AC grid structure.