中文摘要：

我国电力系统正在形成交直流互联的巨大网络,交直流系统操作及故障、直流换流阀的动作、负荷变化产生的ns、μs、ms级的电磁暂态将在直流系统和交流系统中交互作用,交直流互联系统的电磁暂态交互作用可对交流系统和直流系统构成危害,特别是导致直流系统的换相失败及闭锁等严重事故。鉴于此,在已有的能比较准确反映交直流互联系统关键元件电磁暂态特征的宽频特性模型基础上,在PSCAD/EMTDC平台上建立计算模型,揭示交流系统对直流侧的电磁暂态传递机理及影响规律。结果表明,交流电网对直流系统的电磁暂态影响较严重,换流站330 kV交流母线的出线发生三相短路故障时,直流极线对地、换流阀两端的过电压达到了1000 kV,超过了绝缘保护水平的设计值。该研究为分析交、直流互联系统电磁暂态交互作用打下了基础。

英文摘要：

The AC-DC system electromagnetic transient interaction of nanoseconds,microseconds,milliseconds electromagnetic transient due to AC-DC system operation and fault,the DC converter valve movement,and the load generated by changes can pose a hazard on AC and DC power systems,in particular,lead to the commutation of DC system failures and serious incident of atresia.Consequently,on the basis of the broadband characteristics model which can accurately reflect the existing AC-DC interconnected system electromagnetic transient characteristics of the key components,we apply the PSCAD / EMTDC platform to build a computational model,and reveal AC side electromagnetic transient interaction on DC side.The results show that the electromagnetic transient effects of AC side on the DC side are more serious,three-phase short circuit fault of 330 kV AC converter station bus occurs when the DC polar-to-ground over-voltage across the valve reaches the 1000 kV,more than insulation level of protection of the design value.