CAJ | 학술논문

详细论述了直流系统单极运行及磁暴引发的变压器直流偏磁的异同点，进而探讨了地磁感应电流(GIC)的等效源建模问题。通过PSCAD/EMTDC平台搭建了计及变压器偏磁效应的双机系统仿真模型，对线路事故过负荷进行了仿真研究，分析评估线路距离保护耐受GIC的能力。仿真结果表明GIC通过中性点接地变压器侵入电力系统后，可能造成变压器铁心不对称饱和，从而使测量阻抗发生周期性波动。距离保护Ⅲ段作为下级变压器的远后备保护，在线路事故过负荷造成负荷转移的情况下，其动作可靠性降低，可能受GIC扰动而发生误动。
상세논술료직류계통단겁운행급자폭인발적변압기직류편자적이동점，진이탐토료지자감응전류(GIC)적등효원건모문제。통과PSCAD/EMTDC평태탑건료계급변압기편자효응적쌍궤계통방진모형，대선로사고과부하진행료방진연구，분석평고선로거리보호내수GIC적능력。방진결과표명GIC통과중성점접지변압기침입전력계통후，가능조성변압기철심불대칭포화，종이사측량조항발생주기성파동。거리보호Ⅲ단작위하급변압기적원후비보호，재선로사고과부하조성부하전이적정황하，기동작가고성강저，가능수GIC우동이발생오동。
This paper describes the similarities and differences between the DC bias’ influences on transformers made by geomagnetic induced current (GIC) and HVDC in detail. Then the simulation of GIC is discussed and a simulation system is built based on PSCAD/EMTDC platform. Then the case of post-fault over load is simulated and the performance of distance protection is analyzed. The result demonstrates that when GIC invades power systems through transformers with neutral grounded the transformer core may become asymmetric saturated, which may cause the measured impedance in the state of cyclical fluctuations and distance protection zone Ⅲ which backs up for adjacent transformer is possible to mal-operate under the case of post-fault over load.