摘要
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。
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.
出处
《浙江电力》
2015年第5期14-18,共5页
Zhejiang Electric Power
