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,采用理论分析及测试相结合的方法建立基于地上交直流互联电网络、控制系统和地下接地系统全波过程的特高压系统电磁暂态精确分析方法,通过研究,最终换流变压器采用UMEC三相双绕组换流变压器模型;直流线路采用考虑频变特性的J-Marti模型;单阀的等效电路由晶闸管、饱和电抗器、阻尼电阻和阻尼电容、铁损电阻、并联均压电容元件组成;直流控制器、直流滤波器、交流滤波器也由相应的电路等值。该研究通过建立直流侧设备的电磁暂态特征的宽频特性模型,为分析交直流互联系统电磁暂态交互作用打下基础。

英文摘要：

Huge interconnected power grids are formed in AC and DC power systems in China.The nanoseconds,microseconds,milliseconds electromagnetic transient due to AC and DC system operation and fault,the DC converter valve movement,the load generated by changes interact in the AC and DC interconnected system,impairing AC and DC power systems,especially leading to the commutation of DC system failures and atresia such serious incidents.Consequently,a theoretical analysis was combined with a test method to establish an over ground network,considering DC electrical networks,control systems and underground grounding system of the full-wave process of the UHV system,Finally,converter transformer was modeled with UMEC model,and transmission line was modeled with J-Marti frequency dependent model;moreover,valve was modeled with transistor,RLC circuit,and other units including DC controller,and DC filter and AC filter were modeled with RLC circuit.The broadband characteristics of electromagnetic transient models of key units in DC sides for the analysis of AC and DC interconnected system were also analyzed.