CAJ | 학술논문

10 kV配电网架空出线通常只安装有两相电流互感器,为获取出线的零序电流,可以在出线空缺相增设1只电流互感器,与另外两相电流互感器组成零序电流过滤器.零序电流过滤器输出特性对出线零序电流的测量至关重要,因此对零序电流过滤器的特性进行了理论分析,搭建了一套零序电流过滤器的试验回路,设计并实施了多项相关试验对零序电流过滤器的输出特性进行试验研究,并在现场进行了应用研究工作.结果表明:零序电流过滤器误差产生的主要原因是构成零序电流过滤器的3只单相电流互感器的铁心饱和特性不同,为最大限度的降低零序电流的测量误差,构成零序电流过滤器的3只电流互感器的额定参数需尽量一致;在变电站出线为架空出线的情况下,用3只额定参数相同的单相电流互感器组成的零序电流过滤器可以从出线中提取出零序电流,幅值误差和相角误差都比较小,可以应用到以零序电流为判据的故障选线装置中;已用于现场实践的零序电流过滤器经过多年的运行,设备运行正常,选线装置选线结果准确可靠,验证了零序电流过滤器的可行性.上述结论可以为利用零序电流过滤器进行10 kV配电网架空出线的单相接地故障选线提供依据.
10 kV배전망가공출선통상지안장유량상전류호감기,위획취출선적령서전류,가이재출선공결상증설1지전류호감기,여령외량상전류호감기조성령서전류과려기.령서전류과려기수출특성대출선령서전류적측량지관중요,인차대령서전류과려기적특성진행료이론분석,탑건료일투령서전류과려기적시험회로,설계병실시료다항상관시험대령서전류과려기적수출특성진행시험연구,병재현장진행료응용연구공작.결과표명:령서전류과려기오차산생적주요원인시구성령서전류과려기적3지단상전류호감기적철심포화특성불동,위최대한도적강저령서전류적측량오차,구성령서전류과려기적3지전류호감기적액정삼수수진량일치;재변전참출선위가공출선적정황하,용3지액정삼수상동적단상전류호감기조성적령서전류과려기가이종출선중제취출령서전류,폭치오차화상각오차도비교소,가이응용도이령서전류위판거적고장선선장치중;이용우현장실천적령서전류과려기경과다년적운행,설비운행정상,선선장치선선결과준학가고,험증료령서전류과려기적가행성.상술결론가이위이용령서전류과려기진행10 kV배전망가공출선적단상접지고장선선제공의거.
The overhead feeder of a 10 kV substation network is usually equipped with two-phase current transformers.In order to obtain the zero-sequence current,a third current transformer is usually installed in the absence-of-phase to form a zero-sequence current filtrator.The output characteristics of the zero-sequence filtrator are vital for the measurement of zero-sequence current for feeders.On the basis of theoretical analysis of the characteristics of the zero-sequence fihrator,we set up a test circuit for zero-sequence filtrator,designed and carried out related laboratory tests,and conducted the field application.Test results indicate that,(1)errors in zero-sequence current filtrator are mainly attributed to the different excitation characteristics of the three single-phase current transformers that composes the zero-sequence current fihrator.In order to avoid the error in zero-sequence current measurement to the largest extent-the three current transformers of the zero-sequence filtrator need to maintain the same specified parameters;(2)in the presence of the overhead feeder in the distribution network-zero-sequence current of feeders could be obtained from the zero-sequence filtrator that is composed of three current transformers with same parameters.The obtained zero-sequence current with relatively small errors in terms of amplitude and phase can be applied in zero-sequence current based feeder detection;(3)application of zero-sequence current filtrator has proven to be accurate in feeder selection,which well infers the reliability of the zero-sequence current filtrator.These findings can provide a criterion for single phase feeder detection for the overhear feeder of 10 kV substation network that uses zero-sequence current filtrator.