Accuracy improvement of impedance-based fault location method for power distribution network using distributed-parameter line model

Abstract

Power Distribution System (PDS) is spread on different places. Therefore, PDS has many laterals and load taps. Accurate fault locating in PDS causes to improve reliability indices and its efficiency. In this paper, an improved method is suggested for fault location in PDS, which has a high accuracy. In the proposed algorithm, by using phase domain of distributed-parameter line model, a fifth-order algebraic equation of fault distance is obtained, which can improve the accuracy of determined fault distance for all types of faults. The proposed method is tested under different fault resistances in which the results show low sensitivity to this parameter. To evaluate the accuracy of the proposed method, the modified IEEE 34 Node Test Feeder is used, and its efficiency and accuracy is proved. distance of fault. In the presented method in [7], the short-line model and phase component are used for DFLS. The suggested method in this paper is tested under unbalanced and non-homogenous condition of a system that has load taps. The accuracy of this method is sensitive to fault resistance and location of fault.Another method for determining distance of single-phase fault on overhead lines in PDS is presented in [8]. In this paper, fundamental frequency component of voltage and current at the beginning of feeder is used. In this paper, the short-line model is also used. This method evaluates the different paths by analyzing the series and parallel impedances. The presented method in [8] is developed in [9] by considering different fault types (double-phase, double-phase-to-ground, three-phase and three-phase to ground). Moreover, different types of conductors are considered for the feeder.Distributed-parameter line model and fundamental component of voltage and current are used for locating of fault in [10][11][12]. In these papers, existence of the laterals and different types of conductors are not analyzed. The introduced method in [12] is based on the distributed-parameter line model. However, in this paper, the phase difference between fault current and branch currents feeding the fault is not taken into consideration. Moreover, in this method, the laterals and loads are modeled with lumped model and R-L-C element.Distributed-parameter line model for single-phase fault in underground distribution system is used in [13] in which existence of laterals, unbalanced operation and different types of conductors are not analyzed.During the fault and transient conditions, capacitive effect of line in PDS cannot be neglected. Therefore, modeling of this effect is very important to obtain the high accuracy in locating the fault in PDS. Line capacitive effect is considered in [14][15][16][17]. An extended method for underground distribution feeders is presented in [15], in which self and mutual impedance and admittance are calculated by Carson's equation. A new equation is presented in [16] for DFLS. In the presented method, by assuming p line model, the impedance-based method is modified and the obtained equation is a second-order ...

Accuracy improvement of impedance-based fault locating method in distribution systems with DGs considering loss of laterals and load variations

“…Obtained parameters in A.6 and A.7 are the corrected form of parameters k 0 to k 5 and kl 0 to kl 5 . In other words, obtained parameters in reference 26 had some defects that have been resolved in this section.…”

“…Figure shows a faulted section in EPDS. In order to determine fault location in the faulted section, the proposed method in Dashti and Sadeh will be used after some modification to consider DGs effects. Also, the final corrected version of some equations, which have inaccuracies and need corrections, are presented in the appendix.…”

Earth fault location determination independent of fault impedance for distribution networks

“…Mora‐Florez et al calculated the fault current based on the positive sequence load current behind the fault point as a function of the fault distance with disconnected DG. Dashti and Sadeh presented an iterative method to estimate the positive sequence load current behind the fault point using a distributed‐parameter line modeling. This yields a fifth‐order polynomial equation for computing the unknown fault location iteratively.…”

“…Filomena et al also calculated the load current iteratively to update the load current of the faulted phase using phase quantities. According to Dashti and Sadeh and Filomena et al, the updating process depends on the total impedance of the faulted phase downstream the faulted section from a load flow during the prefault period.…”

Current reference strategy with explicit negative sequence component for voltage equalization contribution during asymmetric fault ride through

“…It is known that grid faults (symmetrical and asymmetrical) are generated by abnormal grid conditions such as phase‐to‐phase or phase‐to‐ground short circuits. The manifestation of these faults at the point of common coupling (PCC) of the REGS depends on the characteristics of the line and the transformers between the fault location and the PCC .…”