Fault Section Identification Based on Per-unit Zero Sequence Current

The research on fast and accurate fault location technology in distribution networks is of great significance. Currently, many methods for fault location in distribution networks have been proposed, but most theories are difficult to solve the problem of fault location in multi branch distribution networks. Therefore, this paper analyzed the characteristics of traveling wave transmission and proposed a discrimination algorithm that uses the polarity of traveling waves to determine the source of fault traveling waves; Then, using the idea of first locating the fault section and then locating the fault point, a multi branch distribution network traveling wave fault location algorithm is proposed based on the configuration of micro PMU (Phasor Measurement Units) devices in the distribution network by combining the two end method and single end method of traveling wave distance measurement. A multi branch distribution network simulation model based on IEEE14 node standard topology was built using MATLAB/Simulink software, the experimental results also showed the effectiveness and the efficiency of the proposed algorithm.

The copper foil shielding layer and armoring layer of the three-core cable and the grounding electrode of the distribution network constitute the grounding network of the distribution network. When a grounding fault occurs in the power grid, a regular ground current distribution is formed in the grounding network. .This paper analyzes the distribution law of the ground wire current in the arc suppression coil and resistance grounded distribution network: for the distribution network with the neutral point through the arc suppression coil and resistance grounded, the active component of the ground wire current of all cable segments without ground faults is Pass-through, that is, the active components of the ground current at the head and end of the cable are equal in magnitude and in the same direction; the sum of the active components of the ground current at the head and end of the ground fault cable segment is equal to the active component of the fault current at the ground fault point. According to this distribution law, this paper proposes a ground fault location method in which the neutral point is grounded by the arc suppression coil and resistance grounded grid, and its effectiveness is verified by simulation.

The addition of distributed generation sources into conventional distribution networks results in several technical challenges for successful operation of distribution network. As far as physical integration is concerned, finding the exact location of fault is a key issue. The coordination between the protection devices existing in the distribution network gets disrupted due to presence of distributed generation (DG). Therefore existing fault location techniques for distribution system will not work properly with penetration of DG. Therefore new fault location schemes for distribution networks with distributed generations (DG) have been developed in the recent times, but there are still problems whose solution needs to be found out. This paper investigates the issues and current state regarding fault location in distribution network with DG. A comparative analysis is carried out in which the merit and demerit of each technique is assessed and some conclusion and suggestion for fault location in distribution system with DG is put forward.

This paper proposes a fault location estimation method for distribution networks considering errors from measurement devices. The method determines the fault location based on the voltage sag and current magnitudes. The fault location is based on faulted section and fault distance measured from one end of the bus. Faulted section is determines by matching the measured voltage and current with a pre-developed data. For multiple faulted sections, ranking analysis is employed to rank the most likely faulted section. Fault distance is calculated from one end of the identified faulted section. By determining the faulted sections, a fault in homogenous and non-homogenous networks can be located. The method has been tested using an actual Malaysian 11 kV distribution network. Different values of measurement errors have been applied, which includes positive and negative values. The test results showed the effectiveness of the method under various uncertainty of error from measurement devices. The proposed method can serve as an alternative technique for estimating fault location in distribution networks.

When the distribution network fails, the operation and maintenance personnel need to quickly determine the fault location and minimize the scope of the inspection line so that the fault repair personnel can accurately reach the vicinity of the fault point to carry out work. Whether the fault location method is advanced and reliable directly affects the power failure time of the power supply user, and further affects the social, economic, and life aspects. Therefore, the fault location of the distribution network needs to satisfy both reliability and accuracy. It is the basis and premise for troubleshooting, isolating and restoring the power supply. The automation level of China’s distribution network is relatively backward, and the reliability of power supply equipment is relatively low, making it difficult to find fault points. If we find out the intelligent algorithms that can meet the requirements of rapid positioning, accuracy and fault tolerance through theoretical research, we can Improve the fault location efficiency very well.

The structure complexity and the extended geographical area are among the factors that create challenges in accurate fault location and detection in distribution networks. The single‐phase to ground (SPG) faults are considered as most frequent reasons for distribution network interruption, which can threaten the network's reliability. Signal processing methods are usually used as common approaches to distinguish and locate faults in distribution networks. This paper proposes a novel scenario to select optimal wavelet packet transform (WPT) coefficients for SPG fault location and a method based on superimposed voltage energy to distinguish the faulty phase according to these coefficients. Furthermore, employing the energies of the superimposed voltages helps to minimize the effects of high resistance faults (HRFs) and load encroachment on the efficiency of the faulty phase detection part. Comparing the obtained results with other scenarios demonstrates the considerable efficiency of the proposed scenario. Finally, with the help of general regression neural networks (GRNN) as machine‐learning tools, a new algorithm is derived for detecting and locating the SPG fault and capacitor bank switching overvoltage (COV). Simulation results are implemented on the IEEE 34‐bus standard distribution network, demonstrating the efficiency and superiority of the suggested method.

The signal source based on signal injection scheme which is the main equipment of fault location in distribution network injects AC constant current signal to fault lines.However, its constant current value can't be changed according to characteristics of lines.This paper proposes a high power signal source which can be controlled remotely through an Android mobile phone application.Firstly, the signal source has remote data sent-receive ability through GPRS module.Then data forwarding is realized by cloud server which has a fixed IP.Finally, data exchange between mobile client application and signal source GPRS module is realized by the connection to the cloud server.This achieves that Android client application can remote control the high power signal source for fault location in distribution network.

A novel plant growth simulation algorithm is proposed for fault location of distribution network in this paper. It presents a way to transform the currents of switches and equipments into integer variables, sets up a model for fault location of distribution network. Simulation tests proved the correctness, effectiveness as well as the high fault tolerance of the above plant growth simulation algorithm based model. It creates a new field for fault location of distribution network.

Ant colony algorithm is a heuristic search algorithm based on population optimization, which is derived from the foraging behavior of real ants in nature. It has the characteristics of positive feedback, fault tolerance and distributed collaborative optimization mechanism, but the ant colony algorithm is easy to fall into local optimum and slow to search. Based on the traditional ant algorithm, this paper applies the improved ant colony algorithm to the fault location of distribution network, establishes the switching function, and divides the distribution network, simplifying the dimension of feasible solution of ant colony algorithm. The simulation results show that the improved ant colony algorithm is effective in the location of the distribution network segment in the case of information distortion and loss.

Based on the existing fault location of distribution network, a novel traveling wave head detection method based on MRSVD decomposition and symmetric difference energy operator is proposed in this paper. Multi-resolution singular value decomposition (MRSVD) is a method that combines matrix binary recursive structure principle and singular value decomposition method. In this paper, the original signal is separated from the high frequency detail components by MRSVD method, and then the energy of teager is calculated to obtain the precise traveling wave arrival time. Then, a multi-terminal traveling wave fault location scheme is proposed, and the fault location is obtained by layer by layer calculation. Finally, the accuracy of the algorithm is verified by MATLAB simulation. Experiments on setting different fault parameters show that the method has good accuracy and practicability.

The low-voltage distribution networks have some structural features, such as short supply line, more lines branch and influence of transition resistance of the short-circuit current. These characteristics seriously affect the development of fault location technology. The paper, based on the basis of the structural features about the low-voltage distribution networks, create the distribution networks of description matrix by knowledge of mathematical topology and use the distribution network fault location algorithm based on web-based structure matrix. By the algorithm, the area of fault judgment and the actual distribution network fault location are fully consistent. The new theory provides a new way of thinking for fault location in low-voltage distribution networks.

Fault location in electrical energy distribution networks is an important task, as faults in distribution grids are among the main causes of electricity supply disruption. Fault location in the distribution systems, however, is a challenging task because of the topology of the distribution networks, as well as the main and side branches. Therefore, it is necessary to address these challenges through an intelligent approach to fault location. In this paper, fault location in electric energy distribution networks is addressed considering the changes in fault distance and fault resistance in the presence of different fault types. A new method for fault location is developed for conditions where the minimum information is available and only information at the beginning of the feeder is used. This facilitates wide adoption of the technique as it does not require significant investments in instrumentation and measurement. The proposed intelligent method is based on the impedance and transient state estimation. This technique employs a specific impedance analysis for determining possible fault locations considering the unbalanced performance of distribution systems, distances, and different fault resistances. To determine the real faulty section, real fault frequency component analysis and the simulated faults at possible fault locations are used. At this stage of the process, it is possible to eliminate multiple estimations with the help of comparison and identification of the similarities. Therefore, a real faulty section is determined. It is observed that some conditions of electric energy distribution networks affect the accuracy and performance of the proposed method significantly; thus, a detailed investigation is conducted to neutralize these conditions. Simulation results and calculations based on MATLAB along with a practical test of the proposed method in power network simulator confirm a satisfactory performance.

Aiming at the problem that the traditional method is difficult to satisfy the fault location of distribution network with charging load, a distribution network fault location method based on graph theory and deep learning under charging load access is proposed. Firstly, the graph theory is introduced to decompose the distribution network topology into several Y-shaped tree structures, and the distribution network topology model is constructed; Then, the fault current characteristics of distribution network during electric vehicle reverse discharge are analyzed. The mapping relationship between response data and fault location is mined by using generalized network learning (GDL), and the fault feature training model is constructed; Finally, graph theory and GDL is used for fine fault location. The experimental results show that the proposed method for short circuit fault are 98.09% and 0.019 km respectively. This method can effectively improve the positioning accuracy, accurately determine the fault section, and has strong fault tolerance.

Distribution network fault location technology is currently mainly concentrated in sub section positioning and based on the offline signal injection method precise positioning stage, this paper proposes a new online traveling wave fault location method based on the correlation matrix, the method based on line distributed terminal high sampling data waves, with terminal data construction association matrix, through the correlation matrix of the symmetry and correlation determine fault section and identify abnormal data set, on the basis of further accurate fault location, so as to improve the reliability and accuracy of fault location in distribution network.

With the rapid development of national economy, the distribution network becomes more and more complex and the load density is increasing. The safe and stable operation of distribution network is crucial to reliable power supply. The faults in distribution network account for a large proportion in the whole power system, and have an increasing trend. Therefore, accurate fault location of distribution lines is of great significance for fast power recovery. At present, the traveling wave fault location of distribution network is usually based on the fault location method for transmission lines. The engineering situation of distribution network is not fully considered and the analysis is simple, which affects the precise analysis of fault traveling wave transient characteristics and the improvement of fault location method. In this paper, the transient characteristics of fault traveling wave under different fault conditions in distribution network are analyzed and the analysis results are validated by simulation.