Overhead Transmission Lines Early Warning and Decision Support System with Predictive Analytics

Overhead transmission lines play a key role in ensuring power system security and reliability in this current smart society. The overhead transmission line operates in a very complex terrain thereby making it vulnerable to various kinds of faults. Most transmission line faults lead to interruption in power supplies and therefore the need for a fast repair to restore the system to its normal state. A fast, timely, and accurate fault detection technique will ensure speedy restoration of the system thereby reducing outage time. In this article, an enhanced transmission lines’ fault detection approach is presented. This scheme deployed a highly sensitive, low cost, and energy-efficient differential sensor to detect flux density variation measured along transmission lines. The fault detection algorithm is developed for the detection of faults in transmission lines. The development is implemented on a model transmission line and tested for various fault scenarios. Scaled-up laboratory experiments were also conducted to measure magnetic flux density and fault identification to verify the validity of the proposed technique as well as estimate the amount of current produced when a fault occurred. From the simulated and measured current produced during a fault, the proposed technique yielded an estimated error of 1.38%, while the CT and a commercial current probe gave errors of 10.99% and 17.68%, respectively.

<span lang="EN-US">Since transmission lines account for 80–86% of power system problems, protecting transmission lines is a critical concern. This research proposes a method to identify and categorize various short circuit defects on transmission lines. Various operational and fault circumstances on the transmission of high voltage lines, including L-L fault, single phase to earth fault, and double line fault, double line Three fault scenarios triple line fault, triple line to ground fault, and triple line are simulated using MATLAB software. These flaws damage the linked devices to the power grid. The main motto of this work is to analyze various kinds of faults and also to detect the type of the fault in transmission line. In order to simulate and evaluate the various faults, a 100 km transmission line model was created. A sim power system block library had a fault block, and the harmonic content of the various faults was studied using the FFT tool, the effect of faults was observed. Based on the analysis, a hardware model is designed to identify the faults in transmission line using actuating relays and Atmega 328P microcontroller and display the fault type and parameters like fault impedance, and distance at which fault occurred.</span>

In electrical power systems, the overhead transmission line (Figure 19.1a) is utilised for facilitating power delivery of electrical energy to consumers despite the long distance separating it from its resources. Standard three phase parallel transmission lines increase the power transmission capability. A schematic diagram of parallel three phase power lines is shown in Figure 19.1b. Compared to the generation and distribution parts of the power system, high failure probability is recorded in the transmission part despite the high standard measures in the design and material selection.

Lightning strikes are the main cause of tripping faults in transmission lines, Great damage to the smooth operation of the power grid. In this paper, the risk assessment model of overhead transmission lines against lightning strikes is based on XGBoost algorithm is constructed by integrating meteorologica, power grid and environmental factors. Taking a city in Guangdong Province as the research object, the lightning trip data in 2021 was screened for verification, The results show that 75% of the fault points are located in the risk area, and the model can identify the high-risk area. The higher the risk level of grid assessment, the greater the probability of lightning trip failure in the grid, which can be used to guide the upgrading of lightning protection equipment.

The complexity of transient processes during travelling-wave propagation in extra high voltage overhead lines is deter-mined by the fact that many frequency components are presented in the electromagnetic wave front. For the correct analysis of the aforementioned transient processes and for further development of travelling-wave-based relay protec-tion and fault location devices, it is necessary to take into account the parameters of the environment where electromagnetic wave propagation occurs. For the transmission line, these parameters are longitudinal inductance, longitudinal resistance, shunt capacitance and shunt resistive conductance. It is worth mentioning that for a variety of reasons unit-area longitudinal inductance and resistance are the parameters which depend on frequency, thus travelling wave velocity is different for different frequency components of the electromagnetic wave front. The popular researches which address this problem either fail to consider the dependence of overhead line inductance and resistance on frequency or this dependence is considered approximately for the high-frequency range, which can cause significant errors in the transient processes analysis during travelling wave propagation. In view of this, the development of the approach to overhead transmission lines simulation, which will allow both determining the line parameters in a wide frequency range and evaluating steady-state behaviour and transient processes in long-distance transmission lines, arrears relevant. The main research method to establish extra-high voltage transmission line parameters employs the simulation study in COMSOL Multiphysics. A number of assumptions were made in the simulation process: homogeneous soil layer, entire transmission line section and absence of transmission line conductor sag. The usage of finite elements method (FEM) for differential equation solution in the above-mentioned software is also seen as an assumption. The approach to extra-high voltage transmission lines simulation has been offered. This approach consists of the usage of Maxwell’s equations in combination with numerical integration with finite elements method (FEM). Frequency response for transmission line parameters and travelling-wave propagation velocity rate for different frequency components have been obtained. The results obtained can be used in updating of electrical power system models for further research in the relay protection field. The suggested approach will allow evaluating line parameters of other voltage types and obtaining more accurate values of transmission line parameters and travelling wave propagation speed along transmission lines for high-frequency range. The use of these transmission line models will enable to formulate approaches to improve the existing algorithms of travelling-wave-based relay protection and fault location devices.

The paper is essentially an overview presenting an outline of how Electro-Magnetic Transients (EMTs) are calculated in power system networks for means of an EMT Program based on travelling wave modelling of transmission lines. This paper presents the following steps: (1) For circuits with lumped parameters, the individual branches are modelled by different equations which are discretized to provide Norton equivalents. These are assembled producing nodal equations, to be solved step-by-step. (2) Transmission lines are modelled by time lags and Norton equivalents, even if their parameters are frequency dependent or multi-phase, in which case model decompositions are used. This paper uses state equations for transmission line modelling. Inclusion of transmission line Norton equivalents in the nodal equations does not complicate the system problem due to the effective time-decoupling of the computations. Some recent developments such as <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Z</i> -transforms, <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</i> -domain analysis and corona modelling are also described.

The article investigates the mathematical model of the power supply system elements – transmission lines. It is shown that transmission lines have a variety of mathematical models. They are the basis for the study of the operating modes of power grids. They reflect all the peculiarities of physical processes under steady state and transient modes and must ensure sufficient accuracy of the results obtained. The type of mathematical model of transmission lines depends on the accepted simplifications, which allow to consider a separate research problem. The purpose of the article is to develop a mathematical model of the power transmission line for the study of the power supply system modes, with the possibility of its application to take into account all structural features of overhead and cable transmission lines, and with the possibility of use in asymmetric modes.

In this paper, the cuckoo search (CS) algorithm - neuro fuzzy controller (NFC) technique is proposed for estimating the electric and magnetic field (EMF) of over head transmission line (OHTL). In the proposed method, the CS algorithm is used to optimize the conductor spacing (arrangements) and to minimize the EMF. From the optimized arrangement of the conductors, the EMF of the transmission lines is evaluated and formed as the datasets. Then the optimized data set values are applied to the input of the NFC. Subsequently, the coordinates are given to the input of the NFC which predicts their corresponding EMF data. The proposed method is implemented in the MATLAB working platform. For testing the performance of the proposed estimation methods, two overhead transmission line models with 110 kV and 400 kV respectively are considered. In order to verify the effectiveness of the proposed method this is compared with the CS algorithm-ANN controller.

Overhead transmission lines, which are directly related to the safe and stable operation of the power grid, are important channels for the transmission of electrical energy. Accurate and efficient detection of electrical components in transmission lines is crucial for maintaining power grid stability and safety. Existing methods often encounter difficulties with issues such as small targets, complex backgrounds, and varying scales. In this paper, we propose an enhanced version of YOLOv8 specifically designed for multi-object detection in transmission line inspections. Secondly, with the aim of enhancing the accuracy and robustness of electrical component identification as well as defect detection, the Faster-Block module, GhostNet, SPD-Conv, and the triplet attention module are incorporated into the original YOLOv8. Finally, improved YOLOv8 and the mainstream deep learning algorithms are trained and tested on the self-built dataset. The mean average precision (mAP) value of improved YOLOv8 reaches 86.73%, which is nearly 36%, 14% and 10% higher than that of Faster R-CNN, DETR, YOLOv8, respectively. In addition, the inference speed of the improved YOLOv8 reaches 38.1 frames per second (FPS), which is 4.4% faster than that of YOLOv8. Ablation studies and comparative experiments demonstrate the effectiveness of our approach in detecting insulators, dampers, clamps, and defects, especially for small targets and complex scenes.

In power system engineering, Transmission Lines (TLs) plays a major role, an important goal of this is to transmit the generated electricity to various distribution units. Transmission lines act as a bridge between consumers and the powerhouse. In the transmission lines, the faults often occur because they are located in open space. Quick detection and recovery of transmission lines faults are necessary to maintain the normal operation of the power system. To overcome these disturbances, techniques like Discrete Wavelet Transform (DWT) and Empirical Mode Decomposition (EMD) are used in fault detection and diagnosis. DWT is applied to decompose the fault transients, because it can simultaneously extract the data, in both time and frequency domain. EMD is used to decompose the transmission line voltages into Intrinsic Mode Function (IMFs). Four types of fault signals are generated from the grid-connected power system. Transmission line faults are created using MATLAB/Simulink.

Faults in transmission lines have several adverse impacts on the overall health of the power system. Circuit breakers and relays help in isolating the fault and protecting the entire system. Prompt tripping of the circuit breakers is a vital aspect of power system protection, to minimize the extent of damage. Numerical relays could provide high degrees of accuracy and precision, supported by their powerful processing systems and the wide range of algorithms that could be incorporated. This paper presents an efficient algorithm to detect unsymmetrical faults, classify the fault type and locate the fault zone in transmission lines using Artificial Neural Network (ANN), which could be implemented in numerical relays. The complete system is capable of identifying no-fault condition, the three different line-to-ground faults, line-to-line faults and double line-to-ground faults, and indicating the zone in which the fault has developed. To locate the fault, three zones have been recognized in each transmission line. The same algorithm is implemented in hardware and results are presented.

With a growing number of wind farms connected to the traditional grid, it may cause a series of instability because the wind power's randomness. In order to analyze that the small-signal stability of the power system whether affected by the different transmission lines between wind farms and the power grid or not? At first, a PMSG (Permanent Magnet Synchronous Generator) model of direct-driven wind turbine was established, and the WSCC (Western Systems Coordinating Council) 3-generator 9-Bus system was taken as the test system. Then, the distribution of the system's eigenvalues was considered under the different penetration rate of wind power. Lastly, the time domain simulation in PSAT was finished. The results showed that the overhead transmission line and the cable have the distinguishing influence on the small-signal stability of the power system when PMSG-Based wind farm conducted to the existing system, using cable as the transmission line can make the system get better small signal stability.

In this paper, according to the ice storm weather, through the numerical analysis of meteorological records, the movement rule of ice storm weather and the mechanism of action on overhead transmission lines are studied, and the ice storm weather model suitable for overhead transmission lines is established. Then the ice storm weather model is connected with the failure probability of the overhead transmission lines, and the structural reliability of the overhead transmission lines under the ice storm weather is analyzed. Finally, based on the evaluation of the reliability of the lines, the restoration model of the damaged overhead transmission lines is established. So as to provide a theoretical basis for the safe operation of the power grid.

Remote monitoring of transmission lines of a power system is significant for improved reliability and stability during fault conditions and protection system breakdowns. This paper proposes a smart backup monitoring system for detecting and classifying the type of transmission line fault occurred in a power grid. In contradiction to conventional methods, transmission line fault occurred at any locality within power grid can be identified and classified using measurements from phasor measurement unit (PMU) at one of the generator buses. This minimal requirement makes the proposed methodology ideal for providing backup protection. Spectral analysis of equivalent power factor angle (EPFA) variation has been adopted for detecting the occurrence of fault that occurred anywhere in the grid. Classification of the type of fault occurred is achieved from the spectral coefficients with the aid of artificial intelligence. The proposed system can considerably assist system protection center (SPC) in fault localization and to restore the line at the earliest. Effectiveness of proposed system has been validated using case studies conducted on standard power system networks.

The purpose of this paper is to investigate the performance of the Frequency-Dependent Lumped Parameter Model (FD-LPM) to adequately represent two distinct overhead transmission lines (OHTLs) subjected to different lightning currents. Frequency-Dependent Lumped Parameter Model (FD-LPM) takes into account the Skin and ground-return effects required to properly represent an OHTL and to compute the electromagnetic transients in power system. The FD-LPM is ruled by state equations in which the longitudinal parameters can be adjusted by a rational function using the Vector Fitting Technique and extended to any Electromagnetic Transient (EMT)-type simulators First, longitudinal impedances of these OHTLs are fitted into a rational function in residue-pole form which are incorporated in the ATPDraw software by the component LIB. Then, time domain responses due to lightning currents are computed under different scenarios. The FD-LPM was employed to represent short lines subjected to lightning strikes whose time domain responses were computed to different step sizes. Furthermore, results were compared with the JMarti's model for and those computed by Numerical Laplace Transform (NLT). Numerical results demonstrate that transient responses obtained with FD-LPM under small step size present a good agreement with those computed by NLT, which are assumed as reference responses.