基于阻抗角的交直流输电系统交互影响分析

采用短路比对交直流输电系统的交互影响分析只考虑了交流系统等值阻抗模值的大小,为了更准确地评估系统稳定程度,需要考虑阻抗角对系统稳定裕度的影响。以单馈入和两馈入直流系统为基础,研究阻抗角和耦合阻抗角对直流系统输送功率极限的影响,并且在CIGER标准模型的基础上,保持系统短路比不变,研究阻抗角对受端交流系统暂态过电压的影响。仿真分析结果表明,当受端交流系统等值阻抗角较小时有利于提高直流系统输送功率极限,增大稳定裕度和提高最大直流功率,同时也有利于改善系统故障后的暂态过电压。

Interaction of the AC/DC Transmission System Based on the Impedance Angle

The analysis of the interaction of AC/DC transmission system with short circuit ratio(SCR) has only considered the AC system equivalent impedance modulus size.In order to more accurately assess the stability of the system,the impact of the impedance angle to system stability margin need to be considered.Based on single-infeed and two-infeed DC system,the impact of impedance angle and the coupling impedance angle to the DC system power transmission limit was analyzed.And with the CIGER standard model,keeping SCR of the system unchanged,the impedance angle to the transient overvoltage of the receiving end AC system was researched.The simulation results showed that smaller impedance angle of DC system can not only help to improve the DC system’s power transmission limit,increase the stability degree and the maximum available power,but also help to improve the transient overvoltage of system after fault.