High‐frequency transient comparison based fault location in distribution systems with DGs

Shi

et al. 2020

IEEE Trans. Smart Grid

128

As a result of small fault current, high level of noise and a large penetration of distributed generators (DG), in the neutral non-effectively grounded medium-voltage (MV) distribution networks, it is quite difficult to locate the faulted line section for single phase to ground faults. In this paper, using a technique based on synchronized measurements in distribution networks, a fault location method based on the analysis of the energy of the transient zero-sequence current in the selected frequency band (SFB) is proposed. The equivalent impedance of the distribution network with lateral branches is studied with an equivalent network, and the phase-frequency characteristics of the equivalent impedance are analyzed. The SFB, within which the transient energy of the faulty line section is larger than that of the healthy line sections is determined. A combined fault-section location criterion is proposed and the implementation scheme is illustrated with the distribution level phasor measurement units. Numerical simulations of the IEEE 34 node system and the field experiments of a 10kV distribution network validate the feasibility and effectiveness of the proposed method.Index Terms--Active distribution networks, fault location, neutral non-effectively grounded system, single phase to ground faults, transient zero-sequence current.

Section: Introductionmentioning

confidence: 99%

Location of Single Phase to Ground Faults in Distribution Networks Based on Synchronous Transients Energy Analysis

Wang

Shi

et al. 2020

IEEE Trans. Smart Grid

128

“…Additionally, the monitoring devices required for traveling wave positioning are expensive, and the practical application of engineering is difficult. e impedance method [11] calculated the impedance of the fault branch by measuring the voltage and current at the fault point, and then calculated the fault distance. Like the traveling wave method, the multibranch of the distribution network affected the accuracy of the method.…”

Section: Introductionmentioning

confidence: 99%

Fault Location Method Based on SVM and Similarity Model Matching

Mathematical Problems in Engineering

Yuan

Shi

et al. 2020

To locate the fault location accurately and solve the problem quickly is the key to improve the power supply capacity of power grid. This paper presents a fault location method based on SVM fault branch selection algorithm and similarity matching. Firstly, an SVM-based fault branch filter classifier was constructed based on the positive sequence component feature matrix data of each monitoring point, which can accurately select the branch where the current fault is located. Then, based on the positive sequence voltage distribution characteristics, the Euclidean distance and Pearson correlation coefficient (PCC) are used to establish the similarity objective function of fault location. And then, the fault is accurately located by the objective function. Finally, the proposed method is validated by using an IEEE-14 node network. The results show that the proposed method is effective and accurate.

“…The transient zero‐sequence current of the faulted line is generally tens of times larger than the steady‐state zero‐sequence current, making it containing more fault information [14]. Thus, many scholars have proposed methods of using the transient zero‐sequence current and voltage [15–21]. The transient zero‐sequence current and voltage of each detection point are analysed with artificial intelligence algorithms such as neural networks to establish distance detection equations for fault location in [15, 16].…”

Section: Introductionmentioning

confidence: 99%

“…Combined with the Pearson correlation coefficient method, the difference of the fault transient zero‐sequence current information at both sides of the fault section is used in [20]. A wide‐area high‐frequency impedance comparison method is proposed in [21] based on the high‐frequency impedance model without knowing the exact parameters of the distribution system. However, the changes in the neutral grounding mode and the grounding resistance of the system have a great influence on the accuracy of the fault section location.…”

Section: Introductionmentioning

confidence: 99%

Research on fault section location method of distribution networks with arc suppression coil grounding based on energy leakage function

Fang

Yan

IET Generation Trans & Dist

et al. 2020

In distribution networks with arc suppression coil grounding, the fault line can be set as the energy leakage channel of the capacitive current of the entire system. During the period from fault occurrence to the whole action process of arc suppression coil, there is abundant fault information in the transient waves. However, the data of this period are usually ignored in previous methods. In this study, a novel fault section location method based on the leakage energy function is proposed. Only the fault phase voltage and fault phase current are used in the proposed method, to avoid the difficulty of the zero‐sequence current measurement. Then, the action characteristics of two types of arc suppression devices are analysed. The influence of the capacitor current on the fault phase voltage and current during the entire process of arc suppression coil operation is deduced. The difference between the leakage energy on both sides of the fault section is used as the criterion for fault section location. Finally, the effectiveness of the method is verified by a case study. The simulation results indicate that the proposed method has high sensitivity and high impedance adaptability, that will have more advantages in the actual situations.