High Voltage Distribution Lines Research Articles

가공 배전선로 진단시스템 프로그램 개발

In this paper, accidents in high-voltage overhead distribution lines, which provide stable power supply in the power system, cause inconvenience in life and disruption of production of companies. 22.9 [kV] high-voltage overhead power distribution lines aim to improve reliability and stability, such as damage caused by rain, snow, wind, etc., or electric shock prevention. Therefore, in order to prevent wire disconnection accidents due to deterioration of electrical conductivity or tensile strength due to corrosion of overhead distribution lines, it is necessary to prevent unexpected accidents in the future through regular inspection and repair. In order to diagnose deterioration due to corrosion of distribution lines, a diagnostic system (measuring instrument) is installed on the wires to monitor the condition of the wires. The manager on the ground receives the measured data through ZigBee wireless communication, controls the diagnosis system through the diagnosis system program, and grasps the condition of the overhead distribution line through the measured data and photographed photos, and predicts the life of the wire along with the visual inspection method. developed a program.

Research on remote emergency control breaking device for trolley type circuit breaker switchgear

High-voltage transmission and distribution lines use circuit breaker switchgear for stopping and feeding operations. Therefore, if abnormal emergencies in circuit breaker shutdown and transmission, it is urgent to carry out remote control switching to solve the problem that the circuit breaker cannot be operated with power when the remote control fails. This paper develops a trolley type circuit breaker switchgear remote emergency control shunting device, which can remotely shunt the circuit breakers on the switchgear and sink control cabinet manually in situ. And we also discusses the hardware and software design principle as well as the advantage analysis to ensure the personal safety of the operators on site and provide reference for improving the safety, economy, flexibility and reliability of the power grid.

An Artificial Intelligence Based Current Measurement Technique in High Voltage Power Transmission and Distribution Lines using Pyro-Sensors

High voltage transmission lines are the fundamental element in order to transfer electricity from the power plant/grid to consumers. The frequency, current and voltage are the key figures to sustain the absolute quality of the power transmission, and maintaining such high performance requires smart solutions and equipment like Current Transformer (CT) & Potential Transformer (PT). This proposed work enlightens an inception to monitor current in the high voltage transmission lines by using pyro-sensors, machine learning (ML) techniques and artificial intelligence (AI). Using pyro-sensors around the transmission/distribution lines, data will be gathered about the heat waves (infrared waves) generated by the electric current in the transmission/distribution line. The proposed methodology uses this data to be processed by neural network based artificial intelligent algorithm to evaluate the amount of current in the transmission line. The claim about the authenticity of the proposed technique is tested and verified by MATLAB simulation neural network toolbox.

Performance of Composite Insulators Used for Electric Transmission under Extreme Climatic Conditions

Composite or polymeric insulators are being used in various parts of the world for high-voltage transmission and distribution lines. In some parts of India, places in the states like Rajasthan and Gujarat experience an increase in the daytime temperature up to 50 degrees C, while the nighttime temperature reduces as low as 3-5 degrees C. Because of these extreme temperature variations along with electric stress and humidity conditions, composite insulators have to perform well over their lifetime to ensure the reliability of the transmission network. In the present work, experimental conditions are simulated with temperature variation from 50 to 3-5 degrees C along with electrical stress, humidity variation, pollution, and ultraviolet radiations. Accelerated aging studies with these stresses are conducted to understand the degradation on the insulator similar to the field conditions. Surface resistivity measurements, leakage current analysis, and surface degradation studies using thermogravimetric analysis, scanning electron microscopy, energy-dispersive x-ray, and Fourier transform infrared spectroscopy (FTIR) are conducted. Some interesting results obtained from the study are presented. Experimentation under extreme conditions with polluted insulators showed considerable degradation which was inferred from the material testing analysis. The insulator slabs on which electrical stress was not applied showed a considerable peak at 1500 cm(-1) in the FTIR spectra, indicating the generation of low molecular weight PDMS chains from the bulk due to UV aging and thermal stress, while the degradation pattern of non-polluted sample was severe compared to the slab treated but was considerably less severe in comparison with the polluted insulator sample exhibiting pollution can considerably increase degradation rate.

Cars and Clouds: New Drivers for Efficient Power Management

The electrification of transportation and the continued expansion of cloud based computing are two drivers for optimizing power efficiency. The automotive power requirements focus on highly efficient transfer from DC to AC (and vice versa), at very high power levels. Current IGBT switching devices are packaged in large modules with extensive cooling capacities. Reductions in size/weight require increased efficiency at higher frequency and current density. The desire for higher efficiency in datacenters is aimed at cost reduction of the total compute environment. Each individual server requires the most efficient power conversion from high voltage distribution lines to very low voltage boards. Switching devices again are packaged in modules, operating at very high power density, requiring co-optimization of devices, connections and packages. To realize the desired combination of size, speed and density, wide bandgap materials may be needed to advance the roadmap of these power management products. We will review some of the recent progress and challenges in materials innovation to optimize device and package and circuit.

Impulse Noise Considerations Related to Data Transmission over High-voltage Lines

This paper describes methods for theoretical modeling of inter-arrival time of impulse noise and presents a new model based on the application of general mathematical distributions, together with its implementation in MATLAB. It also discusses the suitability of this model for development and testing of digital communication systems intended for deployment on high-voltage power distribution lines. DOI: http://dx.doi.org/10.5755/j01.eee.20.8.8444

Con Edison's Success in Reducing Risk: Applying Real-World Lessons Learned to Broaden Spill Planning and Response Programs and Build Personnel Competencies

ABSTRACT Con Edison's service territory covers more than 1,000 miles of inland and coastal shoreline in one of the most heavily regulated and scrutinized areas of the Unites States: New York City. In November 2009, the company experienced a catastrophic failure of a large transformer at a high-voltage electric substation, resulting in approximately 200 gallons of dielectric oil impacting the Bronx River. While the volume of oil was relatively small, the duration of the cleanup lasted nearly one month with costs of approximately $1.75 million, plus a nearly $1 million compliance order issued by New York State for violation of state regulations. Following this event, and through a study of all historical spill incidents, it was clear that the primary risk of spills to the environment came from the more than 30 million gallons of oil contained in the company's high-voltage transformers and oil-filled electric transmission and distribution system, which were not covered by existing Facility Response Plans developed as part of implementing OPA 90. Given these results, the company sought to refine existing spill response program elements to further reduce risks and enhance environmental stewardship. Using the existing Spill Management Team (SMT) model in the OPA 90 program, a company-wide SMT approach was created to better prepare for and reduce the risks associated with potential spills from all company sources. The team consists of more than 50 personnel from the various business units of the company, providing direct access to a wide spectrum of skill-sets and specialties. In addition, the company has developed Oil Spill Contingency Plans (OSCP)—also covered under OPA 90—with detailed response tactics for over 300 locations. On the heels of the program implementation, a large spill of dielectric oil from an underground high-voltage electric distribution line resulted in more than 2,000 gallons impacting the Hutchinson River. While the impact to the waterway was greater than in the 2009 event, the response duration was only 6 days with clean-up costs just over $300,000 with no state issued compliance order, a significant improvement. This result was due, in large part, to implementation of the OSCP and SMT programs. Through these experiences, the many benefits of establishing a company-wide SMT and the OSCP's were realized, including developing spill response and Incident Command System expertise, refined coordination, and improved cost management. These efforts have significantly reduced the company's spill risk exposure by improving response capabilities.

The Effects of Induction Motor Parameters on its Low Voltage Ride through Capability

The induction motor (IM) is important equipment among industries. When voltage sag occurs, both the protective device like reclosure mounted in high voltage transmission and distribution lines and the terminal undervoltage tripping of contactor will make the IM disconnect away from the utility, with its terminal voltage changed from voltage sag to interruption. The IM will continue to operate because of inertia. The first-order dynamic model between slip, load torque and terminal voltage is set up based on IM steady-state equivalent circuit. And the universal analytic functions of slip and critical time are deduced from the model which can be used to evaluate the IM low voltage ride through (LVRT) capability, thus providing reference for the designation of IM.

An Evaluation Method for Power Supply Capability of Distribution System Based on Simplified Grid Structure

This paper proposes a method to evaluate power supply capability of distribution system considering the connection mode of high voltage network. Firstly, based on the operation mode and load transfer of distribution network, the grid structure is simplified by forming incidence matrices between main transformers and high voltage distribution lines. Then a nonlinear programming model of power supply capability is developed through N-1 contingency analysis of high voltage distribution lines and main transformers, and the power supply capability of a distribution system can be obtained by solving the relevant model. The correctness and effectiveness of the proposed method are verified by a case study.

Evaluation of Effect of Residential Energy Demand Management to Mitigate Voltage Increase in High-Voltage Distribution Line Due To Large-scale Diffusion of PV

Evaluation of Effect of Residential Energy Demand Management to Mitigate Voltage Increase in High-Voltage Distribution Line Due To Large-scale Diffusion of PV

High-Voltage, High-Performance Switch Using Series-Connected IGBTs

A high-performance, high-voltage switch obtained by a series connection of 3300 V insulated gate bipolar transistor (IGBT) modules is presented. The correct voltage sharing between the devices is ensured by the presence of a simple and reliable auxiliary circuit, which acts as a feedback on the gate terminal. A comparison in terms of power losses, output currents, and switching performances to a single 6500 V IGBT module is also presented. An extended experimental analysis demonstrates strong advantages in terms of switching losses (up to 67%) and current and voltage gradients. Use of trench-gate IGBTs, available in the 3300 V size but not in the 6500 V one, allows extra performance to the series connection circuit, as experimental results show. Such circuit is suitable to increase performances of high-power, high-voltage inverters used in railway traction, in high-voltage energy distribution lines, and in high-power solid-state klystron modulators.

Computational Aspects of Electromagnetic Fields near H.V. Transmission Lines

Biological effects of electromagnetic fields on the human body, animals and plants have been a subject of scientific interest and public concern for their risk on the living organisms such as blood leukemia and others. The high voltage transmission and distribution lines, which pass beside some houses, factories and schools are source of electromagnetic fields. This paper presents the field calculations around and near of high voltage transmission lines 220 kV and 500kV. To calculate the induced current, the power density, the electric field and the magnetic field of grounded and ungrounded human body cylindrical model are used. MATLAB program package is used for mathematical calculation of the distribution of the EMF in human body under high voltage power transmission lines.

반복계산법을 이용한 철도고압배전계통의 고장점표정 알고리즘

High voltage distribution lines in the electric railway system placed according track with communication lines and signal equipments. Case of the over head lines is occurrence the many fault because lightning, rainstorm, damage from the sea wind and so on. According this fault caused protection device to wrong operation. One line ground fault that occurs most frequently in railway high voltage distribution lines and sort of faults is line short, three line ground breaking of a wire, and so on. For this reason we need precise maintenance for prevent of the faults. The most important is early detection and fast restoration in time of fault for a safety transit. In order to develop an advanced fault location device for 22.9[kV] distribution power network in electric railway system this paper deals with new fault locating algorithm using flow technique which enable to determine the location of the fault accurately. To demonstrate its superiorities, the case studies with the algorithm and the fault analysis using PSCAD/EMTDC (Power System Computer Aided Design/Electro Magnetic Transients DC Analysis Program) were carried out with the models of direct-grounded 22.9[kV] distribution network which is supposed to be the grounding method for electric railway system in Korea.

PSCAD/EMTDC를 이용한 철도 고압 배전계통의 과도특성 해석 및 1선 지락사고에 대한 보호방안

철도에서의 고압배전선로는 역사조명 및 동력설비, 그리고 열차의 안전운행을 위한 신호설비의 전력을 공급해 주는 설비로 열차의 안전운행 및 철도 이용자의 서비스 향상을 위한 중요한 역할을 담당하고 있다. 또한 각종 전력기기의 전자화, 자동화로 인해 양질의 전력공급이 요구되며, 철도 이용자에 대한 보다 향상된 서비스를 제공과 역사내 전기에너지 사용의 급증으로 인한 전력공급의 신뢰성 확보가 요구된다.BR 본 논문에서는 철도고압배전계동의 고장현상을 분석하기 위하여 철도고압배전 설비중 접지계통과 비접지계통에 대해서 사고시 전압강하가 발생 여부와 사고를 제거하기 위해 차단기를 동작시켰을 때의 서지전압에 의한 과도특성을 PSCAD/EMTDC를 이용하여 모의하였으며, 이 사고모의 결과를 토대로 비접지 고압배전계동의 보호방법에 대한 대안을 제시하였다.

The Measuring and Protection Method for the Abnormal Rise of Magnetizing Inrush Current in a Divided Type 3 CTs System

This paper describes the measuring and protection method for the abnormal rise of magnetizing inrush current in a divided type 3 CTs system. By divided type 3 CTs system, it is possible to measure the primary phase current and zero phase current at the same time. In this reason, the divided type 3 CTs system is widely used for the measurement of high voltage distribution line by simply clamping the each phase lines with 3CTs. For the accurate measurement of the phase current and zero phase current, the internal residual current in CT should be small as possible. It is reported that the abnormal rise of the residual current is generated in the practical field use and several ten ampere (converted to the primary current value) is observed in some case. The abnormal rise of the residual current is caused by the primary magnetizing inrush current or by the sum of the influence by electromagnetic field of the nearby conductors. The magnetizing inrush current is caused by the magnetic saturation of the core of CT. It is difficult to eliminate the abnormal residual current by using the bigger size of core. In our test, we used the active elements and independent feed back coils around the right and left core of CT. By using the feed back current from these coils it was observed that the magnetic saturation of the core is improved and the magnetizing inrush current can be controlled.

各種インパルス電圧による架空絶縁電線表面の沿面放電特性

When the lightning occurs at the neighborhood of outdoor high voltage distribution lines, the creeping discharges propagate along the wire surface from the binding wire tip just after the flashover of insulator. These discharges give rise to the various disasters at distribution lines, for instance, disconnection and melting of wire, punch-through breakdown etc. We must clarify the creeping discharge characteristics under various inductive lightning surges from a viewpoint of a safety in high voltage distribution systems. In our previous paper, it was reported that the lengths and aspects of the negative creeping discharges were influenced by the duration of wave front of impulse voltage applied to the central line under the grounded binding wire. The present study was accomplished in order to obtain more information on such creeping discharges.This paper describes the distinctive characteristics of creeping discharge along the insulated wire surface when the impulse voltages with various durations of wave front are applied to the binding wire.

Fiber-Optic-Based Current and Voltage Measuring System for High-Voltage Distribution Lines

A system for temporary measurement of voltage and current simultaneously in high-voltage distribution lines was developed. The sensing heads use a resistive divider and a magnetic pickup for sampling voltage and current, respectively. A self-powered transmitter converts both signals into a pulse-frequency-modulated optical signal for transmission in multimode optical fiber. At ground potential, the optical signal is received and demodulated back into voltage and current signals. Then, a microcontroller calculates V and I for the three phases as well as VA, power factor, and watt-hour, storing these in memory. The system exhibits all data in instantaneous mode and stores 5-min mean values of a period of up to ten days. Optionally, the data can be collected by a personal computer through a standard RS-232C serial port. The system linearity for both current and voltage is better than 2% in the range of 0 to 800 A and 0 to 15 kV, respectively. It can be installed by live-line techniques in less than 10 min, without de-energizing the line.

Development of high voltage harmonic measuring instruments for distribution systems using optical voltage sensor and current sensor

Application of an optical measuring technique was attempted in order to develop harmonic voltage and current measuring instruments for distribution systems. To develop the harmonic voltage measuring system using a Bi12GeO20 crystal as a sensing Pockels cell for high-voltage distribution lines, zinc oxide elements were adopted as a voltage divider. Also, an optical current sensor system was improved on the harmonic current measuring system using an R3Fe5O12 film as a Faraday device. In practical three-phase distribution systems, the developed high voltage harmonic measuring devices using the optical voltage sensor and current sensor were compared with conventional harmonic analyzers for low voltage. As a result, it was confirmed that the developed high voltage harmonic measuring devices had satisfactory characteristics for practical use. © 1999 Scripta Technica, Electr Eng Jpn, 128(4): 84–93, 1999

A new protective method for grid connected dispersed PV systems to detect short circuit fault in distribution line

A new protective meausre installed in the grid connected dispersed PV system for detecting short circuit fault with high-resistance in a high-voltage distribution line was designed. Relationship between voltage absolute value change and voltage phase change of the distribution line is monitored in the measure for achieving not only enhancement of detective performance but also prevention of misdetection in normal operation of the grid. It was clear from simulation results that the number of PV systems detecting the fault increased about 2 times as much as the existing method and the reduction of fault current at utility substation, which causes dangerous inability of utility's protection, could be prevented effectively.

A Shunt Active Power Filter Applied to High Voltage Distribution Lines

A Shunt Active Power Filter Applied to High Voltage Distribution Lines