Cable Distribution Research Articles

An equivalent investigation of space charge for plane samples and coaxial cables under a temperature gradient

In this research, the equivalence of space charge for coaxial cables and plane samples are analyzed through simulation. Bipolar charge transport models of coaxial cables and plane samples are established with the same material-dependent parameters, the bulk charge and total space charge distributions are simulated and comparatively researched under isothermal and temperature gradient conditions. The presented results indicate that the space charge behavior shows a basic equivalence in terms of charge variation laws and distribution. In addition, few discrepancies in the heterocharge amount and charge waveform amplitude are observed and mainly ascribed to the sample geometry, mobility gradient distribution and the spatial resolution of the measuring system, respectively. Investigations of space charge characteristics with a plane pulsed electro-acoustic measurement system may be accepted as a practice for providing the space charge characteristics of coaxial cable insulation, unless it is necessary to investigate the cable space charge distribution under actual operating conditions.

Optimization of cable-stayed bridges: A literature survey

This literature survey concerns the application of optimization techniques to cable-stayed bridges. A search within the Web of Science and Scopus electronic databases was conducted, complemented by a hand search. From a total of 155 articles, 90 were chosen for a detailed review. The search results are summarized, highlighting the procedures, the main conclusions and contributions of each work.The optimization of the cable forces distribution and the optimum design through cost minimization is present in 80% of the publications. In the last decade, optimization algorithms were used for a wide range of applications, such as, the design of hybrid fiber reinforced polymeric deck and cables, structural health monitoring, assessment and identification of existing bridges, design and location of passive and active control devices to improve the dynamic performance.The detailed analysis showed that the optimization of footbridges, long-span bridges and multi-span bridges with innovative cable arrangements like crossing-cables are attracting the interest of researchers. Moreover, the optimization taking into account the wind action, the seismic action and other dynamic effects are areas of major concern in future developments.

High Impedance Fault Detection and Location in Combined Overhead Line and Underground Cable Distribution Networks Equipped with Data Loggers

Power distribution networks are vulnerable to different faults, which compromise the grid performance and need to be managed effectively. Automatic and accurate fault detection and location are key components of effective fault management. This paper proposes a new framework for fault detection and location for smart distribution networks that are equipped with data loggers. The framework supports networks with mixed overhead lines and underground cables. The proposed framework consists of area detection, faulty section identification, and high impedance fault location. Firstly, the faulty zone and section are detected based on the operation of over-current relays and digital fault recorders. Then, by comparing the recorded traveling times at both ends of lines, which are related to the protection zone, the faulty line is identified. In the last step, the location of the fault is estimated based on discrete wavelet transform. The proposed method is tested on a 20 kV 13 node network, which is composed of overhead lines and underground cables. The method is tested in both balanced and unbalanced configurations. The obtained results confirm the advantages of the proposed method compared with the current state-of-the art.

ANALYSIS AND METHODS OF ORGANIZING NODE PART OF THE ACCESS NETWORK

This paper presents results of developing a models and methods for organizing a node part of an optical access network. The object of research is optical cross of the GPON, and the subject of research is models and methods for reducing its resource consumption and increasing other parameters characterizing its functioning. Models and methods are proposed for choosing the type of equipment for optical cable distribution system, as well as a model and method for choosing the structure of switching connections that solve the problem of minimizing the amount of resources.

Mechanical behaviors and experimental study of submerged floating tunnel subjected to local anchor-cable failure

Submerged floating tunnel (SFT) is a new type of cable-supported structure system for strait crossing. Once the local anchor-cable suddenly fails, it will inevitably cause evident vibration and internal force redistributions of the structure. In order to study the dynamic responses and mechanical behaviors of the SFT subjected to abrupt anchor-cable breakage, a model test is conducted by a set of sensors installed on SFT for cable force, tube displacement and strain measurements. The transient dynamic signals following cable failure are tested and analyzed. Dynamic amplification factor (DAF) and dynamic coefficient (DC) are respectively used to evaluate the impact effect from the cable failure. Meanwhile, finite element simulations are also performed within ABAQUS. The establishments of the finished state of SFT before cable breakage and the dynamic cable failure process are presented both in the model test and FE model. Comparisons between the FE predicted values and the experimental results show a good agreement. On this basis, some influence factors are discussed in different cases of the cable-loss positions and the cable forces of ruptured cable, etc. The results show that the finished state of SFT under dead load (tube redundant buoyancy) after cable-force optimizations is more reasonable than that directly applying dead load without any cable-force adjustments, with more uniform cable force distribution and smaller tube deformation. Although the SFT suffers strong oscillations after sudden cable-breakage incident, no progressive collapse occurs when the safety margin of the rest structure is sufficient. The dynamic effect on remaining cable members due to sudden cable failure can be evaluated by DC method. A DC value of 1.5 is recommended to ensure the safety of SFT anchor-cables. When cable failure happens at the mid span of the tunnel, the deformation of SFT tube is most critical.

Simulation study on ±320kV DC power cable steady-state temperature field distribution and its influencing factors

Temperature distribution is an important parameter in the operation of DC cables, while there are few studies at present. In this paper, the steady-state temperature field distribution of DC cable was calculated by simulation, and the factors including conductor current and outer surface temperature were discussed and analyzed. The results showed that there is a temperature gradient in the radial direction of the cable; Both the conductor current and the outer surface temperature have a significant effect on the overall temperature of the cable; The increase in the conductor current and the outer surface temperature will significantly increase the conductor temperature. However, the insulation temperature difference changes little.

A Cumulative Expansion Force‐Finding Method for Suspension‐Cable Truss Composite Structure

Suspension‐cable truss composite structure is a new type of cable‐strut structure which combines the conventional cable structure with the rigid truss. By laying rigid roofing slabs, this composite structure offsets most effect of the wind suction, reduces the axial force of the stable cables, and reduces the large vertical displacement effectively when compared with conventional cable trusses. For this new structure, the deformation relevance between adjacent substructures results in a nonindependent and stable union. To effectively and precisely find the cable forces of a suspension‐cable truss composite structure for the construction completion state, a proper optimization order and a suitable selection of the substructures are necessary. In this paper, the structural mechanical characteristics of the suspension‐cable truss composite structure are introduced at first, to reveal the force transmission path between adjacent substructures. Secondly, the cumulative expansion force‐finding method (CEFM) is proposed to obtain the optimal mode of the cable force distribution with a suitable operational efficiency. A numerical example is introduced and analyzed to verify the accuracy and feasibility of this method afterwards. The results show that CEFM could find out the optimal cable force distribution of the suspension‐cable truss composite structure, with a geometry shape of whole structure and a rational stress level of all the components.

Incipient Fault Location Method of Cable Based on Both-End Electric Quantities

The early fault of a cable is usually a incipient fault, which is difficult to find and can easily develop into an insulation breakdown fault. Thus, it is of great significance to quickly and accurately find an incipient cable fault. This paper presents an fault location method for cable insulation based on the electric quantities of both ends. Based on the equivalent circuit model of three-phase single-core cable distribution parameters, the calculation method of the voltage along the cable is derived. The equivalent model of cable insulation in resistive and capacitive parallel is proposed and applied to the early fault modeling of cable. On the basis of the calculation formula of the voltage along the cable and the electric quantity at both ends of the cable, the analytical expression of the cable fault location is obtained by solving the fault equation directly. Extensive simulations show that the algorithm, this method can locate the incipient fault accurately, and is not affected by the fault point, fault resistance and fault inception angle.

Neuro-Fuzzy Access for Detection of Faults in an Underground Cable Distribution System

Nowadays, the interest of power system engineers In Indian Power System has increased towards the use of underground cables with the advent of cross-linked polyethylene (XLPE) insulated cables having high capacity for transmission of power. Underground cables are preferred in the densely populated regions where there is environmental constraint and right of way poses a big problem. The key limitation of underground cable is to locate and detect different types of faults in view of the fact that the cables are lying down under the surface. It is necessary that the fault must be cleared in minimum time on account of protection issues. As conventional methods for detection and classification of faults are time consuming, so, this work uses intelligent techniques for fast and more accurate detection of location and classification of faults in underground cables. Overall work has been performed in three steps, the first step is to develop a MATLAB/Simulink Model of a distribution system using underground cable with a provision to develop fault. In second step, an Artificial Neural Network (ANN) using DWT is used for fault detection & classification. In third step, ANN is hybridized with fuzzy system and discrete wavelet transform (DWT) methods to improve its performance. The training sets of adaptive neuro fuzzy inference system (ANFIS) are energy components of three phases of cable under fault (used as inputs) and fault type or different distances of faults in the cable(used as outputs). All the simulations have been carried out in MATLAB/ SIMULINK environment

Study on Stiffness-Oriented Cable Tension Distribution for a Symmetrical Cable-Driven Mechanism

In this paper, we focus on the issues pertaining to stiffness-oriented cable tension distribution for a symmetrical 6-cable-driven spherical joint module (6-CSJM), which can be employed to construct modular cable-driven manipulators. Due to the redundant actuation of the 6-CSJM, three cables are employed for position regulation by adjusting the cable lengths, and the remaining three cables are utilized for stiffness regulation by adjusting the cable tensions, i.e., the position and stiffness can be regulated simultaneously. To increase the range of stiffness regulation, a variable stiffness device (VSD) is designed, which is serially connected to the driving cable. Since the stiffness model of the 6-CSJM with VSDs is very complicated, it is difficult to directly solve the cable tensions from the desired stiffness. The stiffness-oriented cable tension distribution issue is formulated as a nonlinear constrained optimization problem, and the Complex method is employed to obtain optimal tension distributions. Furthermore, to significantly improve the computation efficiency, a decision variable elimination technique is proposed to deal with the equality constraints, which reduces decision variables from 6 to 3. A comprehensive simulation study is conducted to verify the effectiveness of the proposed method, showing that the 6-CSJM can accurately achieve the desired stiffness through cable tension optimization.

Potential Energy Distribution of Redundant Cable-Driven Robot Applied to Compliant Grippers: Method and Computational Analysis.

Cable-driven parallel robots with a redundant configuration have infinite solutions for their cable tension distribution to provide a specific wrench to the end-effector. Redundancy is commonly used to increase the workspace and stiffness or to achieve secondary objectives like energetic minimization or additional movements. This article presents a method based on energy distribution to handle the redundancy of cable-driven parallel robots. This method allows the deformation and tension of each link to be related to the total energy available in the parallel robot. The study of energy distribution expression allows deformation, tension, and position to be combined. It also defines the range of tension and deformation that cables can achieve without altering the wrench exerted on the end-effector. This range is used with a passive reconfigurable end-effector to control the position of two grippers attached to some cables which act as compliant actuators. The relationship between the actuators’ energy and their corresponding gripper positions is also provided. In this way, energy measurement from the actuators allows the grasping state to be sensed. The results are validated using multibody dynamic software.

"The Conundrum of ‘Relevant Market’: Market Definition in India’s Complex TV Distribution Business"

The universal problematic of market definition poses peculiar challenges in multi-lingual and fragmented media markets, like in India. This article engages with this problematic by taking up the case of the TV distribution market in India. Here, the rapidly expanding TV distribution business consists of two segments. The larger, wired Cable distribution segment, driven by over 1,000 large cable companies and over 50,000 last mile operators, accounts for 70 percent market share, or around 100 million TV homes. The rest 30 percent is occupied by the wireless segment, comprising 6 Direct to Home TV distributors. Amidst the heightened expansion of the TV distribution business during the last decade, we notice a series of cases at the Competition Commission of India (CCI) pertaining to ‘relevant market’. This paper provides a critical appraisal of CCI’s engagement with ideas of relevant geographical market and relevant product market during the first five years of such matters coming to it, i.e. between 2011 and 2015. Focussing on core concepts deployed in debating relevant markets, viz. substitutability and service area, the paper unravels conceptual and methodological challenges provoked by market definition in complex media landscapes such as India.

FPGA-Based Degradation and Reliability Monitor for Underground Cables.

The online Remaining Useful Life (RUL) estimation of underground cables and their reliability analysis requires obtaining the cable failure time probability distribution. Monte Carlo (MC) simulations of complex thermal heating and electro-thermal degradation models can be employed for this analysis, but uncertainties need to be considered in the simulations, to produce accurate RUL expectation values and confidence margins for the results. The process requires performing large simulation sets, based on past temperature or load measurements and future load predictions. Field Programmable Gate Arrays (FPGAs) permit accelerating simulations for live analysis, but the thermal models involved are complex to be directly implemented in hardware logic. A new standalone FPGA architecture has been proposed for the fast and on-site degradation and reliability analysis of underground cables, based on MC simulation, and the effect of load uncertainties on the predicted cable End Of Life (EOL) has been analyzed from the results.

An electrical power control system for explorer-class remotely operated underwater vehicle (ROV)

The importance of an optimal method for electric power transmission is crucial for ROV operation. Meanwhile, only few studies have shown the effect of electrical power system from power supply to ROV.This paper proposes a design and implementation of electrical power system for ROV that developed by Tech_SAS team from Telkom University, Bandung, Indonesia. This work aims to obtain the optimal power system to supply ROV’s electrical and electronic components. Tech_SAS ROV is developed to compete on 1st and 2nd ASEAN MATE Underwater Robotic Competition. The system has demonstrated that 48V electric voltage can be transmitted to ROV with negligible voltage drop when using 20 meter 12AWG cable. The voltage is converted to 12V using DC-DC converter in order to supply various ROV’s electronic devices ROV safely and efficiently. Meanwhile, the microcontroller was used to as thrust control to manage current flow to DC motor. The system has been evaluated and demonstrates optimal results and provides a design consideration about ROV’s power system especially on tether cable and power distribution scheme.

Research on Quantitative Relationship between Fire Separations and Ampacity in Underground pipe gallery Electric cabin

In recent years, underground pipe gallery has become more and more important. Its Special working environment makes temperature monitoring and control increasingly important. paper applies heat-transfer differential equation to the cable to obtain the similarity criterion of cable temperature distribution. After calculating the electric cabin model with different fire separations, it is found that the temperature distribution of the same ampacity in different fire separations conforms to certain rules. The temperature distribution of different ampacity in the same fire separation is also regular: the ampacity rises. 5%, temperature rises by 7%. As a result, the fitting formulas of the current carrying capacity, the length of the fire separation and the location of the highest temperature were also proposed.

Assessment of Selected Securities in Media Industry, India

This research paper would highlight the significance of the media and entertainment industry consists of film, print, radio, and television. These segments include movies, TV shows, radio shows, news, music, newspapers, magazines, and books. The Government of India has supported Media and Entertainment industry’s growth by taking various initiatives such as digitising the cable distribution sector to attract greater institutional funding, increasing FDI limit from 74 per cent to 100 per cent in cable and DTH satellite platforms, and granting industry status to the film industry for easy access to institutional finance. In this paper to revise the fluctuations in share prices of selected companies, Stock market is a market where a number of securities are traded such as equity shares, debentures, bonds, insurance products, mutual funds etc. mostly the existing securities are traded in this market. India has one of the oldest stock markets in Asia and this stock exchange is the Bombay Stock Exchange which was established in 1875.

Improved Speed Sensorless Vector Control Algorithm of Induction Motor Based on Long Cable

In many applications, especially electrical submersible pump required remote operation of inverter via a long motor cable. The conventional control algorithm of induction motor (IM) didn’t operate effectively, which ignored the influence of the cable length, and didn’t consider the effect of long cable distribution parameters. A speed sensor technique was also difficult to achieve. In this paper, an improved speed sensorless vector control algorithm (ISSVCA) for IM based on long cable was proposed. Based on the analysis of long cable motor drive system of the inverter, the two-port π network model of the long cable was established. The functional relationship between the voltage/current parameters of the two ports of the long cable and the cable distribution parameters was deduced. The function expression was transformed to the α − β stationary reference frame, the accurate motor terminal voltage/current was calculated, so that the flux model was constructed to realize the observation of the flux, accurate velocity identification, and closed-loop control of the torque, flux and current. Simulation and experimental results showed that the proposed ISSVCA based on long cable increased the starting electromagnetic torque, decreased speed dip and speed recovery time caused by sudden loads, reduced the DC current harmonics, and had good dynamic and static characteristics.

Исследования распределения магнитного поля силового трёхжильного кабеля 6(10) кВ в рабочих и аварийных режимах с позиции электробезопасности

Исследования распределения магнитного поля силового трёхжильного кабеля 6(10) кВ в рабочих и аварийных режимах с позиции электробезопасности

ANALISIS RUMAH KABEL BAWAH TANAH PADA PROYEK PEKERJAAN JARINGAN UTILITAS SKTT 150 KV PLUMPANG - GAMBIR

Underground cable distribution channels to be excellent especially in big cities like Jakarta. This is because the underground cable distribution is a solution to the difficulty of land acquisition that will be used for top cable networks. Nevertheless, there is an important factor to be considered in implementing the underground cable distribution channel that is the condition of the soil through which the cable. This study aims to determine the dimensions of the cable house was safe from the soil instability. The soil instability are the stability of bolsters and the shear stability and take into account the carrying capacity of the foundation used. The data used as a reference in the analysis using research data that has been done previously. In stability analysis and foundation bearing capacity used Geo5 software demo version aid. The results obtained from the analysis, with variations on the dimensions of the cable house used are 2 mx 2 m, 2.5 mx 2.5 m and 3 mx 3 m, it is seen that the greater the dimensions used then the security number of stability bolsters, soil shear stability and the carrying capacity of the foundation decreases. This is due to the greater the dimensions of the cable house used, the greater the burden borne by the soil.

Research on Controllable Stiffness of Redundant Cable-Driven Parallel Robots

In this paper, to solve the problem of variable stiffness of cable-driven parallel robots (CDPR), a new static stiffness analysis and cable tension distribution method are proposed for studying the CDPRs’ controllable stiffness. First, a three-dimensional Hessian matrix of the structure matrix to position differential is deduced by introducing a line vector and differential transform, and a static stiffness model is established for analyzing the relationship between cable tension and the stiffness of the robots. Furthermore, a calculation algorithm for cable tension polygons based on Graham's Scan is introduced that effectively obtains the cable tension feasible region (CTFR) of CDPRs. Next, a method involving “the relationship between the external force and the pose change value of the moving-platform” is proposed to measure the variation of system stiffness. The CDPR's controllable stiffness is also analyzed based on the CTFR by considering the variation of each driving-cable's tension and each component of the moving-platform's pose. The results of experimental and theoretical analyses verify the correctness and efficacy of the proposed method. In addition, they show that the proposed method is computationally efficient and easily establishes the relationship between cable tension and the CDPR's controllable stiffness.