CAJ | 학술논문

通过阐述变压器零序电流产生机理,指出变压器各相铁芯饱和差异是产生零序分量的根本原因.基于EMTDC/PSCAD平台系统分析了剩磁、合闸角和变压器中性点接地方式对励磁涌流零序电流基波分量最大值的影响,分析结果表明当达到实际最大剩磁时通过调整合闸角可以获得最大零序电流基波分量.仿真分析还发现线路零序过流加速段保护在较大的励磁涌流零序电流下有误动风险,建议通过提高零序过流加速段定值或增加二次谐波制动原理来提高保护的可靠性.
통과천술변압기령서전유산생궤리,지출변압기각상철심포화차이시산생령서분량적근본원인.기우EMTDC/PSCAD평태계통분석료잉자、합갑각화변압기중성점접지방식대려자용류령서전류기파분량최대치적영향,분석결과표명당체도실제최대잉자시통과조정합갑각가이획득최대령서전류기파분량.방진분석환발현선로령서과류가속단보호재교대적려자용류령서전류하유오동풍험,건의통과제고령서과류가속단정치혹증가이차해파제동원리래제고보호적가고성.
Through the description of the generating mechanism of the zero sequence current transformer, this paper points out that the different core saturation of each phase of transformer is the fundamental causes of the zero sequence components. Based on EMTDC/PSCAD, the effect of residual magnetism, closing angle and the neutral grounding mode of transformer on the maximum of fundamental component of magnetizing inrush zero sequence component is analyzed. Results show that when the residual magnetism is maximum, adjusting the closing angle can obtain the maximum of zero sequence current fundamental component. In addition, it is found by simulation that there is disoperation risk in the line zero sequence overcurrent accelerating protection caused by the larger inrush current zero sequence component. Improving the reliability of protection by increasing the zero sequence current acceleration setting value or twice harmonic restraint principle is suggested.