CAJ | 학술논문

传统站域电流差动后备保护，存在当比率系数单调变化时，区内区外故障的灵敏性呈现相斥变化的缺点；以及在区外故障CT饱和情况下保护误动的弊端。为了克服上述缺点，提出了相位相关电流差动的站域后备保护算法。理论分析表明其随着比率系数的单调增加，在区内与区外故障灵敏性都增加；而随着接地电阻的增大，其相较传统差动灵敏性提高；同时其还能克服传统站域电流差动在区外故障CT饱和情况下保护误动的缺点。最后利用PSCAD软件搭建了站域模型，仿真结果验证了理论分析的正确性。
전통참역전류차동후비보호，존재당비솔계수단조변화시，구내구외고장적령민성정현상척변화적결점；이급재구외고장CT포화정황하보호오동적폐단。위료극복상술결점，제출료상위상관전류차동적참역후비보호산법。이론분석표명기수착비솔계수적단조증가，재구내여구외고장령민성도증가；이수착접지전조적증대，기상교전통차동령민성제고；동시기환능극복전통참역전류차동재구외고장CT포화정황하보호오동적결점。최후이용PSCAD연건탑건료참역모형，방진결과험증료이론분석적정학성。
There is a drawback in traditional substation area current differential protection, when the scale factor k monotonously changes, the sensitivity of the internal and external fault will vary oppositely. This paper proposes a substation-area backup protection based on phase related current differential which use the multi points redundancy information. The analysis shows that when the scale factor k monotonically increases, sensitivity of the internal and external fault will increase together. As the increasing of ground resistance, sensitivity of fault will increase. On the other hand, when the external faults cause CT saturation, the traditional protection will mis-operate, but the new algorithm can overcome the shortcoming. At last, PSCAD/EMTDC is used to build a 220 kV substation model, simulation results verify the theoretical analysis.