CAJ | 학술논문

针对HVDC(高压直流输电系统)存在的谐波失稳问题，通过计算电网动态过程中直流线路向整流、逆变两侧的等效阻抗，指出HVDC交直流两侧特定谐波的等效阻抗是研究谐波放大失稳的关键。根据PSCAD/EMTDC仿真软件中的HVDC电磁暂态模型，针对不同工况模拟计算。仿真结果表明，换流变铁心饱和导致了HVDC基频等效阻抗的实部减小甚至为负值，使其应对扰动的阻尼效果减小从而可能诱发HVDC谐波振荡失稳。
침대HVDC(고압직류수전계통)존재적해파실은문제，통과계산전망동태과정중직류선로향정류、역변량측적등효조항，지출HVDC교직류량측특정해파적등효조항시연구해파방대실은적관건。근거PSCAD/EMTDC방진연건중적HVDC전자잠태모형，침대불동공황모의계산。방진결과표명，환류변철심포화도치료HVDC기빈등효조항적실부감소심지위부치，사기응대우동적조니효과감소종이가능유발HVDC해파진탕실은。
Aiming at harmonic instability in HVDC (high-voltage direct current) transmission system, the pa-per calculates equivalent impedance seen from the DC line to both converter and inverter sides in the power system transient state and indicates that equivalent impedance of particular harmonic at AC side and DC side of HVDC is the key of harmonic amplification instability research. Simulation and calculation is carried out in different operating conditions by use of HVDC electromagnetic transient model in PSCAD/EMTDC software. The simulation shows that the core saturation of the converter transformer leads to decrease or even negative value of real part of the converter DC side fundamental equivalent impedance, resulting further instability and oscillation in the system because of the damping reduction.