| Title |
Evaluating Method of Voltage Stability Margin of HVDC Embedded AC Power System Using Direct Calculation |
| Authors |
이제림(Je-Rim Lee) ; 이근준(Geun-Joon Lee) ; 차한주(Han-Ju Cha) |
| DOI |
https://doi.org/10.5370/KIEE.2024.73.7.1095 |
| Keywords |
Direct voltage stability limit calculation; Thevenin equivalent circuit; HVDC embedded system; voltage stability margin |
| Abstract |
AC power systems incorporating HVDC are parallel to existing AC transmission networks, hence the stability of the voltage changes according to the power transmitted by HVDC. Particularly, in power systems that use HVDC to transport the output of renewable energy sources over long distances, frequent changes in transmission power occur due to high source variability, and the evaluation of voltage stability in AC power systems with embedded HVDC becomes increasingly important for ensuring system stability. This paper proposes a method to directly calculate the critical power for voltage stability in AC systems incorporating HVDC, without relying on simulations, using Thevenin equivalent circuits. This method was applied to the IEEE-30 bus system and PSS/E sample 45 bus system, and compared with PSS/E P-V simulation results, yielding practical outcomes. Additionally, the impact of HVDC operating power on voltage stability was analyzed when varying the operational power of HVDC from zero to its rated capacity, providing significant findings regarding the effect of HVDC operation on voltage stability. |