基于S变换的改进双端法配电网故障测距

An Improved Double-End Fault Location Method for Distribution Network Based on S Transform

提出了一种新型双端配网故障测距测方法,基于S变换对传统的双端行波法进行了改进。针对零模和线模电压行波受频散效应、混叠效应等各种因素影响畸变严重、上升沿缓慢难以读取而且后续折反射波信息无法利用的问题,利用S变换对非平稳信号的的分频段呈现作用,读取波形极值即可对初始波头以及后续若干波头进行精确标定,从而提高了双端法的精度,进而实现了只需一对测量端即可对有二级分支的配网线路进行故障定位,简化了设备需求,节约了成本。在PSCAD及Matlab仿真中验证了本方法的有效性和准确性。

A new type of double end distribution network fault location method is proposed. The traditional double terminal method of traveling wave is improved based on S Transform. Aimed at problems such as ： zero modal voltage traveling wave and line modal voltage traveling wave are hard to read and subsequent reflection wave information can- not be used for the serious distortion and slow slope-rising edge caused by various factors such as fre-quency-disper- sion effects, aliasing error, etc. The S transform is unique in that it provides frequency-dependent resolution while maintaining a direct relationship with the Fourier spectrum. Taking advantage of the spectrum feature of S Transform, we can calibrate the position of the first and subsequent several wave precisely only by reading some extreme values. Consequently, the accuracy of double-end method got improved, thus to realize accurate fault location of distribution network with secondary branch only using one pair of measuring terminal. So as to simplifie the equipment needs and save the cost. PSCAD and Matlab simulation proved the validity and accuracy of this method.