Types Of Transmission Lines Research Articles

The Research of real-time identification system of types of lightning failures of UHV transmission lines based on UV detection technique

Egineering running experience shows that with the increase of the operating voltage of the transmission line, the lightning trip rate is increasing. According to theoretical calculation ， UHV transmission lines should be provided with full lightning protection characteristics；however，running experience shows that the lightning withstand level of UHV transmission lines is high，not completely lightning protection; it puts forward higher requirements for lightning protection design of UHV transmission line in China. UHV transmission line is mainly against direct lightning stroke characteristics， one is caused by lightning counterattack trip，the other is the shielding failure of lightning around the line to strike the wound caused by the wire. The lightning fault type identification is based on the micro topography of UHV transmission tower，accumulation of historical data，the development of a more targeted and high voltage transmission line lightning protection scheme is of great significance. In this paper, a real-time identification system based on UV detection technology, which has high accuracy and fast response time, is proposed for lightning fault types of UHV transmission lines, the systems use ultraviolet light to realize online detection of high-voltage transmission line tower nearby lightning, can effective observation tower near lightning discharge, and it has the characteristics of continuous detection, longdistance, no power supply, no contact and no disassembly, it provides an advanced technology for the detection of lightning discharge in UHV transmission line.

Defect diagnosis technology of typical components on transmission line based on Fully Convolutional Network

This paper presents an intelligent defect diagnosis algorithm based on fully convolutional neural network for typical transmission line components. Based on the region-based fully convolutional neural network algorithm and combined with deformable convolution, feature context fusion, clustering, the feature expression ability of neural network is improved. Through the improvement, the algorithm adapts to the object deformation and scale difference. In addition, the training effect is improved by improving the sample labeling strategy. In this paper, the defect diagnosis of four kinds of transmission line components(insulator, vibration damper, grading ring, wire clamp) is realized.

Non-Linear Finite Element Approach to Aerodynamic Effects on Horizontal Taut Cable

A horizontal taut cable which has application in a typical power transmission line was subjected to structural nonlinear static analysis. Finite Element Analysis (FEA) approach was employed in this study to ascertain the magnitude of tension on each node on the cable occasioned by induced aerodynamics forces. ANSYS 14.0 software helped in determining the behaviour of the system on the basis of finite element displacement method. Comparison was made between the two FEA cases with respect to the effectiveness of the analytical model which describes the response in form of a couple of degrees of freedom (DOF) while reflecting the complex features of the dynamics of the cable in reaction to the induced aerodynamic effect. In order to avert excessive displacement in the computations, it was necessary to incorporate the convergence procedure in the process. The optimum deflection of the parabolic response obtained from the analytical Finite Element Method (FEM) results in the absence of aerodynamic external effect was at the nodes 12 and 13 corresponding to cable weight of 1.002936N and cable tension of 189396.97kg/km. The cable also showed a maximum displacement of 4483.75mm for the X, Y and Z components at nodal point 2 while the minimum displacement value was 4218.75mm. The obtained result for this study revealed a complex modal behaviour as is quite expected.

In-plane free vibrations of multi-span transmission lines

A theoretical method of in-plane mode and natural frequency of multi-span transmission lines is presented. The main idea is to establish moment balance equations of each insulator string and in-plane vertical motion equation of each span in multi-span section when the effect of conductor inertia component parallel to the chord on the additional horizontal tension of conductor is considered. The validity of theoretical mode and natural frequency is demonstrated by consistency with the numerical results of a typical five-span transmission line based on ABAQUS. It is shown that the mode of the five-span transmission line with a larger elasto-geometrical parameter exhibits asymmetrical shape that differed from those of single-span conductor. Considering the complexity of the theoretical expression, a simplified theoretical formulation of the modes and natural frequencies of multi-span transmission lines is obtained. Based on the curve of the frequency changing with the elasto-geometrical parameter, the various internal resonance conditions are discussed.

High Phase Order Transmission Line Fault Types

For high phase order (HPO) transmission systems, a major hurdle to overcome is the fault analysis and protection studies needed to guarantee successful implementation. This paper presents new equations which calculate the number of fault types and significant fault types of n-phase transmission lines. In addition, this paper defines and explains symmetrically significant fault types for HPO transmission systems. Lastly, this paper figuratively shows the significant fault types and symmetrically significant fault types for multiple HPO systems, n = 3, 4, 5, 6, 9, and 12. The equations and figures presented in this paper will assist in fault analysis and protective relay designs for HPO systems. The equations presented are used to determine the number of fault types a relay will need to account for, and the figurative approach shows the faults to be studied before HPO implementation.

New spiral beam screen design for the FCC-hh injection kicker magnet

The injection kicker system for the Future Circular Collider (FCC-hh) must satisfy demanding requirements. To achieve low pulse ripple and fast field rise and fall times, the injection system will use ferrite loaded transmission line type magnets. The beam coupling impedance of the kicker magnets is crucial, as this can be a dominant contribution to beam instabilities. In addition, interaction of the high intensity beam with the real part of the longitudinal beam coupling impedance can result in high power deposition in the ferrite yoke. This gives a significant risk that the ferrite yoke will exceed its Curie temperature: hence, a suitable beam screen will be a critical feature. In this paper, we present a novel concept - a spiral beam screen. The fundamental advantage of the new design is a significant reduction of the maximum voltage induced on the screen conductors, thus decreased probability of electrical breakdown. In addition, the longitudinal beam coupling impedance is optimized to minimize power deposition in the magnet.

Fault Classification on a Power Transmission Line Using Discrete Wavelet Transform and Artificial Neural Networks

Classifying and identifying the disturbances in power transmission lines have been challenging tasks for accurate and reliable protection of power transmission line. This paper deals with the design of a Discrete Wavelet Transform (DWT) and an Artificial Neural Network (ANN) based on relay for transmission line fault classification. Applying any form of wavelet transforms produces details, which are related to high frequency components, as well as approximations, which are related to low frequency components at each level of resolution. A simulation setup is developed for collecting various phases’ currents waveforms for purposes of selecting the optimal mother wavelet and the number of levels of resolutions. The Daubechies (db5) mother wavelet with one level of resolution is found to be optimal in providing adequate information in order to detect and classify transmission lines faults. The proposed approach is used to classify shunt and series faults. The proposed algorithm is tested using MATLAB/Simulink on a data collected from a typical transmission line.

ВІРТУАЛЬНИЙ ІНСТРУМЕНТАРІЙ ДЛЯ ДОСЛІДЖЕННЯ ХВИЛЕВОДУ ПРЯМОКУТНОГО ПЕРЕТИНУ

The rectangular waveguide is the most common type of transmission line in millimeter, centimeter, and short-wave part of decimeter range. It allows to transmit quite significant levels of power with a small attenuation, is broadband and mechanically strong. The mode of operation of the transmission line is characterized by a number of parameters, which during its operation are subject to control and are maintained within certain limits by the prescribed adjustments. In order to study waves in a rectangular waveguide for educational purposes, it is often enough to simulate a computer model that can replace a complex of valuable equipment. In this work, a virtual table in a LabView environment, which allows to carry out simulation in order to determine electromagnetic wave parameters in a rectangular waveguide, is synthesized. For a wave of a given type with arbitrary coupling of m and n indices propagating over a waveguide with given geometric dimensions of the cross section, it is possible to determine critical wavelength or critical frequency. Also, the developed virtual toolkit allows to investigate the dispersion in the waveguide, to estimate the value of losses in the waveguide and the efficiency, to determine, separately for the waves of E and H types, characteristic resistance of the waveguide and reflection coefficient. Analytical expressions are obtained to calculate the breakdown power of a waveguide in the propagation of waves of E and H types, which are also implemented as appropriate virtual instruments. The developed virtual toolkit allows to organize distance learning. The synthesized virtual table is a convenient tool for studying the parameters and characteristics of a rectangular waveguide, and when used in the learning process, it will contribute to improving the understanding of the physical processes occurring in the propagation of wavelengths of E and H types in the waveguide.

A Simplified Dielectric Material Characterization Algorithm for Both Liquids and Solids

A simplified dielectric material characterization technique that combines an equivalent impedance algorithm and a general “line–line” trace method is introduced. The technique is applicable to every type of transmission lines. Due to the convenient fabrication and the allowance of integration with various polymers, coplanar waveguide transmission lines integrated with an SU-8 microfluidic channel is primarily used in this study. The conformal mapping method, an efficient and straightforward way, is introduced to build the foundation of dielectric material characterization and to optimize the sensor design. A validation measurement of the proposed technique is performed on deionized water, and show valuable consistency with previous reliable data presented in the literature. Next, the technique is applied on solid SU-8 characterization with four groups of on-wafer measurements. SU-8 measurement results and the related uncertainty analysis are demonstrated subsequently.

Transient Analysis and Mitigation of Resonant Faults on Half-Wavelength Transmission Lines

This paper presents an analysis of resonant faults and their transient responses on half-wavelength lines. This type of transmission line has been studied for many years in countries that need alternatives for bulk power transmission over very long distances. An important issue for this technology is the occurrence of critical faults, which produce peculiar behavior in the main electrical entities and can jeopardize line insulation and compromise system stability. Here, the main factors influencing the severity of faults are analyzed: the type of fault and fault location. This paper shows that faults involving positive and negative sequences are the most critical when applied at specific regions and produce high voltage and power with a high rate of rise. The necessity for a mitigation method that removes this severe resonant fault condition until the operation of a protection system is discussed, and such a method is established. A method using two spark gaps with a new and improved location criterion is proposed, tested and evaluated, providing promising results for controlling voltage and power at terminal substations. Digital simulations are performed with PSCAD/EMTDC.

Impact of anodic bonding on transmission loss in 23GHz pressure transducers

This paper analyses the impact of anodic bonding technique on the transmission loss in 23GHz pressure transducers. The transducers consist of a thin high resistivity silicon membrane and a 23GHz planar resonator placed inside a cavity. Two types of transmission line are used here for designing the resonators: probe-fed coplanar lines and aperture-coupled microstrip ones. Transducers based on aperture-coupled microstrip resonators and manufactured from the anodic bonding process for assembling the silicon membrane to the glass substrate are the most promising low-loss solution. It is actually shown that, at the resonant frequency of the planar resonator, the measured transmission loss in a probe-fed coplanar transducer is about 4 dB when using bonding with the photoresist as an intermediate layer, while it is only of 2.55 dB when applying the anodic bonding assembling process. However, we report for the first time that very high and unexpected transmission loss (>30 dB) occurs when using anodic bonding technique to manufacture the 23GHz aperture-coupled microstrip transducers.

Design and Implementation of a Novel Microstrip Filter

Microwave filters are circuits which perform signal processing functions, particularly to eliminate unwanted frequency components from the signal, to enhance wanted ones, or both. Electronic filters can be passive or active(depends on components used) Analog or digital(depends on input signal) High-pass, Low-pass, Band-pass, Band-stop or all other pass (depends on frequency) Infinite impulse response (IIR type) or Finite impulse response (FIR type) (Depends on response) Microstrip is a type of electrical transmission line which can be fabricated using printed circuit board technology, and is used to convey microwave frequency signals. Microwave components such as antennas, couplers, filters, power dividers etc can be formed using microstrip line. This paper aims on filter design, using microstrip transmission line, with a Non-Periodic technique especially using Defected Microstrip Structure to be operated in the C – Band frequency.

Development of the Electromagnetic Theory of Radio Waveguides

The review of methods of calculation of irregular waveguides is presented. The history of the appearance of waveguide equations and methods for solving systems of waveguide equations for various types of transmission lines is observed.

Mechanistic Insight into Porous Electrode Impedance: An Example of Ni+YSZ Cermet Anodes

Optimization of SOFC electrodes requires detailed insight into their electrochemical processes and rate limiting steps. The impedance spectroscopic investigation of symmetrical cells with two equal electrodes on a solid electrolyte measures not only the area-specific polarization resistance of the electrodes, but physically motivated equivalent circuit modelling and fitting also gives detailed insight into the electrochemical reaction mechanisms and rate limiting processes. In this paper, we give a comprehensive introduction into impedance modeling of porous electrodes and show that a transmission-line type equivalent circuit that is mathematically analogous to the Adler-Lane-Steele model is perfectly applicable to Ni+YSZ cermet anodes. The equivalent circuit fit yields the effective ionic conductivity of the cermet structure, which enables determination of the YSZ phase tortuosity factor. In addition, we can measure the characteristic electrochemically active thickness of the anodes, which gives a direct guideline for the optimal thickness of the fine grained anode active layer in a full SOFC.

Broadband transition from a high‐isolation transmission line to microstrip line

A broadband transition from a novel high-isolation quasi-TEM transmission line (TL) to microstrip line is presented. The proposed design exploits a gradual transition to ensure electric field transformation and impedance matching between two types of TLs. The prototype is designed using back-to-back configuration and fabricated. The measurement reveals maximum insertion loss of 1.4 dB and return loss better than 15 dB from 0.5 to 20 GHz.

Fast Current-Only Based Fault Detection Method in Transmission Line

When a fault occurs in transmission lines, first, it is detected, then classified, and finally, located by a distance protection. Having a fast fault detection approach helps saving the required time for the whole protection procedure. In this paper, a novel method for fault detection of transmission lines based on the summation of squared three-phase currents (SSC) and a moving average technique is proposed. The SSC is constant during a normal condition of the network, while it has considerable variation under a fault condition. Using a moving average concept, a criterion is defined, by which fault occurrence can be detected. The proposed fault detection method is evaluated in four different systems: a typical 5-bus system, a typical double-circuit transmission line, WSCC 9-bus system, and a laboratory small-scaled system. The results confirm a high degree of accuracy and speed of the proposed approach. Moreover, the performance of the method is compared with some other similar methods from different aspects.

Transmission Attenuation of 110kv Asymmetric Transmission Lines Based on Measured Data

The characteristic of traveling wave transmission has great influence on the location precision of the fault point. In order to accurately evaluate the transmission and attenuation characteristic of actual traveling wave on transmission lines, a typical asymmetric arrangement 110kV transmission line is selected as the research object. First, the parameters of the transmission line are calculated, and the traveling wave decoupling algorithm is derived. Then, the traveling wave current collected by the distributed traveling wave monitoring system on the line is analyzed. The results show that for a short distance asymmetric 110kV line, it can be decoupled by the conventional decoupling balance line method, and the coupling component ratio is less than 2% after decoupling. With the increase of transmission distance, the attenuation degree of traveling wave increases. When the transmission distance is 60km, the attenuation of line mode is 21.2% and the zero mode attenuation is 50.4%.

EXPERIMENTAL DEFINITION OF PRIMARY CONSTANTS OF THE ELECTRICAL TRANSMISSION LINES

The article describes the method of experimental determination of the primary constants of the lines of transmission of electrical energy. Analysis of the problem on the basis of modern scientific publica-tions has been performed. It is shown that the experiment is the only reliable way to determine the constants. The use of mathematical models of field theory is impossible, since the magnetic and dielectric constant of line materials are never known for sure. The proposed method is based on accurate mathematical models of the propagation of electromagnetic waves in lines with distributed parameters. Mathematical models for a shielded line with one wire and with two wires are used. Mathematical models are obtained on the basis of Kirchhoff's laws for lines with distributed parameters and are accurate. To perform the measurements, only the simplest measuring devices are used — an ammeter, a voltmeter, and a phase difference meter. An oscil-loscope can be used as a phase difference meter. The experimental data for stranded armored cable are giv-en. Based on these data, the calculation of the primary constants. Verification of the primary constants ob-tained from the experiment was performed. For verification, the substitution of constants into a mathemati-cal model of the propagation of electromagnetic signals in lines with equal parameters was used. According to this model, voltages and currents are calculated at the beginning and at the end of the cable. Comparison of the obtained data with experimental data. The error in determining the constants was no more than 5%. The accuracy achieved is sufficient for most practical cases and can be improved by increasing the meas-urement accuracy. The proposed method for determining the primary constants is universal and can be ap-plied to all types of transmission lines of electrical energy. The article identifies possible areas for further research.

Discharge voltage prediction of UHV AC transmission line–tower air gaps by a machine learning model

Full-scale discharge tests of transmission line–tower air gaps are costly and time-consuming, and they cannot exhaustively simulate all the gap configurations in practical engineering. In this paper, a machine learning model established by support vector machine is introduced to predict the switching impulse discharge voltages of the ultra-high-voltage (UHV) AC transmission line–tower air gaps. The three-dimensional finite element models of a UHV cup-type tower and a UHV compact transmission line were established for electric field calculation, and some features were extracted from the hypothetic discharge channel and the shortest path between the bundled conductor and the tower. These features under a given voltage were normalised and input to the SVM model, while the output is two binary values, respectively, representing gap withstanding or breakdown. Trained by experimental data of one type of the UHV transmission line–tower gaps, the SVM model is able to predict the discharge voltages of another gap type. The mean absolute percentage errors of the two engineering gap types, under different gap distances, are 8.31 and 4.86%, respectively, which are acceptable for engineering applications. The results provide a possible way to obtain the discharge voltages of complicated engineering gaps by mathematical calculations.

Optimal sizing strategy for energy storage system considering correlated forecast uncertainties of dispatchable resources

This paper, from the perspective of hourly dispatch, proposes an approach of sizing Energy Storage System (ESS) in an isolated grid. The objective is to minimize the total cost by optimizing the size of ESS, thermal units generation power, wind curtailment and load demand response. While transforming the chance constraints, such as the network constraints, into the deterministic constraints, the model takes into account the correlations of the forecast errors among wind farms, and load at different buses. In addition, two types of transmission line overloading probability (TLOP) constraints are considered in the ESS sizing models. In particular, an approach of linearizing the scenario generation network constraints is proposed, so that the commercial software can solve the optimization problem. Meanwhile, the performance of the proposed sizing method is validated on a 4-Bus system and a modified IEEE RTS-79 system.