CAJ | 학술논문

直流偏磁可能影响电流互感器(TA)的暂态传变特性,威胁差动保护的正确动作和电力系统的安全运行。与高压直流输电(HVDC)引起的直流偏磁相比,地磁感应电流(GIC)产生的偏置磁通对TA暂态传变特性的影响情况更为复杂,GIC本身的随机性和时变性决定其不能与纯直流引起的偏磁视为等同,而应加以区分。文中研究了由 GIC 及由 HVDC 引发的直流偏磁对 TA 影响的异同。结合TA等值电路,对GIC引起TA饱和的机理进行分析,并在PSCAD/EMTDC中构建仿真模型,根据GIC的特征用低频余弦量对其进行模拟。仿真分析了由GIC引起的TA暂态饱和及局部暂态饱和现象,研究了其对变压器差动保护的影响。研究表明,GIC可能通过影响TA的暂态传变特性从而对变压器差动保护产生影响,GIC对电网安全稳定运行的威胁需引起重视。
직류편자가능영향전류호감기(TA)적잠태전변특성,위협차동보호적정학동작화전력계통적안전운행。여고압직류수전(HVDC)인기적직류편자상비,지자감응전류(GIC)산생적편치자통대TA잠태전변특성적영향정황경위복잡,GIC본신적수궤성화시변성결정기불능여순직류인기적편자시위등동,이응가이구분。문중연구료유 GIC 급유 HVDC 인발적직류편자대 TA 영향적이동。결합TA등치전로,대GIC인기TA포화적궤리진행분석,병재PSCAD/EMTDC중구건방진모형,근거GIC적특정용저빈여현량대기진행모의。방진분석료유GIC인기적TA잠태포화급국부잠태포화현상,연구료기대변압기차동보호적영향。연구표명,GIC가능통과영향TA적잠태전변특성종이대변압기차동보호산생영향,GIC대전망안전은정운행적위협수인기중시。
DC bias may affect the transferring characteristics of the current transformer,threatening the operation of differential protection.Compared with the DC bias caused by high voltage direct current (HVDC) transmission,the bias magnetic flux resulting from geomagnetically induced current (GIC) is more complex,especially when considering its effects on current transformer transferring characteristics.The differences between GIC bias and DC bias are analyzed in detail.According to the equivalent circuit of current transformer,the mechanism of current transformer saturation due to GIC is discussed.Then based on the characteristics of GIC,simulation models are developed in PSCAD/EMTDC,where low frequency sinusoidal currents are adopted to emulate GIC.Simulations are conducted to analyze current transformer transient saturation and partial transient saturation,the results of which demonstrate that effects of GIC may result in mal-operation of transformer differential protection,and should be given prompt attention.