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.
