Electric Power Equipment Research Articles

STUDY OF THE MANUAL POWER EQUIPMENT OF TRACTION ELECTRIFICATION SYSTEM OF THE RAILWAYS

Purpose. Investigation of the operation of power equipment of traction substations (TS) of Ukrainian electrified railways. The search of the new modern methods and approaches improved monitoring, diagnostics and maintenance of power equipment TS during operation to maintain the required level of reliability of the traction power supply of electrified railway and limit the power equipment accidents TS. Methodology . The study of changes of a technical condition of TSs ’ equipment over the last 11 years was done for achieving this goal. This research was done for solving problems of power supply railways with high quality on the base of the reports analysis of the management and power supply of Ukrzaliznytsia. Findings. It was found that on the base of the new methods of maintenance is the risk analysis of old equipment or equipment with some defects (rev servicing equipment for the actual technical condition).Reliable performance of power supply devices has significant impact for solving the problem of safety on the railways of Ukraine. Different kinds of accumulated damage are at the first place before of failures of an electric power supply of electrified railway. The study of main causes of violations from 2002 to 2012 year showed that 80% of the reasons disorders normal operation of the traction power supply over the period constitutes next factors. There are damage to the main power equipment TS; power off the grid; overload and surge; and the impact of weather conditions. The primary power equipment failure of TS are constituted about 43%. Relevant constant monitoring, testing and diagnostics of the equipment with the creation and use of micro-processor smart automated monitoring and diagnosis are topical in the current operating conditions. Originality. The new directions for further improvement of maintenance electrified traction substations for electrified railways were considered. Modern strategies and management techniques and maintenance TS electrified railways of Ukraine were proposed at the first time. This methods aren’t covered in the Instructions for maintenance and repair of equipment of traction substations, power points and sectioning electrified railways ’ IT-0024. The basic problems for implementation of these strategies were identified. Practical value. It was established that system outage under tight central planning and management in the new economy does not provide, in many cases, approval and adoption of effective and optimal solutions in organization and carrying out maintenance. It was investigated that a significant portion of electric power equipment of TS even after normative life maintains its performance under the terms. There are allowable stress regimes, timely testing, diagnosis, maintenance, repair and quality of execution; on the other hand the service life of electrical equipment depends on its residual life.

Trends and problems in development of the power plants electrical part

The article discusses some problems relating to development of the electrical part of modern nuclear and thermal power plants, which are stemming from the use of new process and electrical equipment, such as gas turbine units, power converters, and intellectual microprocessor devices in relay protection and automated control systems. It is pointed out that the failure rates of electrical equipment at Russian and foreign power plants tend to increase. The ongoing power plant technical refitting and innovative development processes generate the need to significantly widen the scope of research works on the electrical part of power plants and rendering scientific support to works on putting in use innovative equipment. It is indicated that one of main factors causing the growth of electrical equipment failures is that some of components of this equipment have insufficiently compatible dynamic characteristics. This, in turn may be due to lack or obsolescence of regulatory documents specifying the requirements for design solutions and operation of electric power equipment that incorporates electronic and microprocessor control and protection devices. It is proposed to restore the system of developing new and updating existing departmental regulatory technical documents that existed in the 1970s, one of the fundamental principles of which was placing long-term responsibility on higher schools and leading design institutions for rendering scientific-technical support to innovative development of components and systems forming the electrical part of power plants. This will make it possible to achieve lower failure rates of electrical equipment and to steadily improve the competitiveness of the Russian electric power industry and energy efficiency of generating companies.

Design of High-Rise Building’s Monitoring System for Electric Fire Base on CAN Bus

This paper accomplished a system of high-rise building’s fire monitoring system based on CAN bus. It is applied in avoiding the harm of leakage current , over current and short circuit, and protecting electric power distribution circuits and electrical equipment, thus to prevent the occurrence of electrical fire. The monitoring system can detect phase current signal and the leakage current signal, and can display real-time and alarm. It also can proceed network service and complete the distributed remote control and fault diagnosis. Practice shows that the system the characteristics of high precision, safe and reliable, low rate of false positives, easy operation and maintenance, etc .It can satisfy the demand of large high-rise building electrical fire.

Special issue of the IEEE Transactions on Dielectrics and Electrical Insulation on Condition Monitoring and Diagnostics of Electrical Insulation

We are pleased to announce that the June 2016 issue of the IEEE Transactions on Dielectrics and Electrical Insulation (TDEI) will be a special issue on Condition Monitoring and Diagnostics topics. The following non-exclusive list of topics may serve as a guideline for prospective authors:  Condition monitoring and diagnostics of electrical power equipment  Diagnostics and monitoring of electrical insulation  Challenges in partial discharge electrical insulation based assessment  Impact of new materials on electrical insulation diagnostics  Emerging diagnostics methods  High frequency methods in diagnostics of electrical insulation  Application of signal and image processing to diagnostics of electrical insulation  Asset management in diagnostics of electrical insulating systems

A Markov Decision Process Model Case for Optimal Maintenance of Dependent Components

This paper is a case study of electrical power equipment to investigate the importance of dependence between series-connected system components in maintenance decisions. A continuous-time Markov decision model is formulated to find a minimum cost maintenance policy for a circuit breaker as independent component while considering a downstream transformer as a dependent component. Maintenance of the dependent component is included implicitly in terms of the costs associated with certain state-action pairs. For policy and cost comparisons, a separate model is also formulated that considers only the independent component. The optimal maintenance policy and its cost differ significantly depending on whether or not the dependent component is considered. Data used are from manufacturer databases; additional model validation could be conducted if applied to an electric utility generation, transmission and/or distribution system. This model and methodology could be applied in other contexts such as industrial mach...

Development of Locating System of Pulsed Electromagnetic Interference Source Based on Advanced TDOA Estimation Method

A locating system based on an advanced time difference of arrival (TDOA) estimation method is developed to locate the position of a discharge source to avoid pulsed electromagnetic interference (PEMI) with the surrounding radio communication environment. In general, from the waveforms of PEMI waves received by an antenna array, the source position can be located or the direction of arrival (DOA) of the EM waves can be estimated by applying TDOA-based methods. However, owing to noises and multipath waves that occur at the metal surfaces of electric power equipment, the estimation accuracy of the TDOA may decrease, and the location accuracy will be degraded. To improve the accuracy of TDOA estimation, we propose a new TDOA estimation technique. In our developed locating system, PEMI waves are received by a four-antenna-square array and the DOA is estimated from the TDOA, which is estimated using the generalized cross-correlation phase transform method in combination with the proposed technique. A PEMI source is ultimately located by aiming a charge-coupled device camera, installed at the center of the antenna array, at the estimated DOA. The estimation accuracy of the locating system is evaluated through experimental measurements. The results show that the developed locating system can locate the position of a PEMI source existing within about 30 m from the system with high accuracy.

Effect of Static Power Supply in Alternator Used for Short-Circuit Testing-Observation of Shaft Voltage

All electrical power equipment, before putting into service, have to pass through numbers of tests to prove their functional performance. In this context, short-circuit test is one of the vital performance tests. A high power alternator used in short-circuit test laboratory is taken as a study object in this paper. Normally, a motor is used as the prime mover for this type of alternator. In this system, the driving motor is eliminated and a thyristor-based static drive is placed to run the machine. The benefit with the static drive is that the single machine can be operated in dual mode, either as a motor or as an alternator. But the negative side of this system is the generation of voltages in the machine shaft. Machine bearings are susceptible to failure if these unwanted shaft voltages cause a high level of bearing currents and persist for a prolonged period. Very little studies were carried out on the power generators related to shaft voltages with perspective to static power supply. This paper explains the details of the static drives applied on this machine for different operational modes. Various causes of generation of shaft voltages are analyzed in view of this special alternator. The outcome of this paper can also be applicable to other large synchronous machines.

대용량 몰드변압기 정밀절연진단 결과 고찰

When the large-capacity Mold type Transformer was passed through rain, after it was dried and it’s parts were changed, Insulation Diagnosis was made to evaluate the condition of it and decide to recharge. Using the evaluation of Insulation Diagnosis, the urgent decision-making for recharge made blackout time minimum. In this study, it was considered that Insulation Diagnosis for the large-capacity Mold type Transformer is applied to decision-making for reuse of high voltage electric power equipment by analysis of the case study.

India’s largest short circuit generator & its salient features

Short circuit test is one of the very important tests on electrical power equipment to verify its design aspects to withstand the critical severities under the condition of actual fault. To perform these tests a high power source is required. This source can be a grid supply with a high fault level or can be a high power short circuit generator. This paper gives the salient features of high power generator installed at Central Power Research Institute (CPRI), Bangalore. This 2500MVA short circuit generator is of highest capacity in the sub-continent of South Asia as on date. The design features are intricate in nature and complex in terms of stator, rotor damper winding and stator end winding. This paper presents the specification, design concept, constructional features, comparison between salient pole and turbo type of generators and other auxiliaries of the generator. Mechanism of achieving the maximum short circuit current is broadly discussed in this paper. This rare facility at CPRI meets high power testing requirement for the electrical industry and utilities of India and other part of the world. In this paper attempts are also made to bring out the highlights of operational features of capital intensive 2500 MVA SC generator. This generator has been used for short circuit testing of various power system components over the period of time.

Danger Classes Detection System Design of High Voltage Transmission Conductor Galloping

Conductor galloping is a kind of phenomenon which is harmful to electric power equipment. If conductor galloping is found and risk assessment is made timely, it can greatly reduce the possibility of line short, open circuit. Currently, it is mainly rely on the way of manual inspection, in which there exists the monitoring blind area. In this paper, an intelligent danger classes detection system design method of conductor galloping based on S3C2410 and CC2530 meter data collecting and processing module. It is mainly responsible for the collection of abnormal accelerated speed information and abnormal recognition of power conductor, and the data through the Zigbee network are transmitted to the control center. The principal computer constituted by software is responsible for the information management, danger classes division of conductor galloping, and giving an alarm. The actual test proves that the system has a higher accuracy of assessment, stable performance and better robustness.

The Analysis and Evaluation of Tendering and Bidding Procurement of Electric Power Equipment Based on Value Engineering

As a main way of electric power equipment procurement, scientific and operational comprehensive assessing index system are essential for successful tendering and bidding. The background and significance of tendering procurement for electric power equipment are introduced in this paper. Aiming at the practice of tendering and bidding procurement, the model of selection of bidding scheme is set up based on value engineering. Empirical analysis of tendering procurement for coal mining machine and atomizing pump proved the feasibility of value engineering analysis in tendering and bidding.

Simulation and Analysis for Damage of Certain Electrical Power Equipment in Battlefield

For the need of simulation research of technical support and obtain basic rush repair data of certain ground-to-air electrical equipment in battlefield condition, this paper studies on the simulation for damage of certain electrical power equipment in battlefield. It analyzes threat mechanisms and basic damage theories of power unit and compiles simulation procedure adopting Monte Carlo method. By simulation, it can analyze vulnerability and distributing of damage parts for electrical power equipment. All this provides reference for rush repair and instruct to defend in battlefield condition.

Development of directly molded bushings and cable sealing ends

Demands that electric power apparatus, and other types of industrial and domestic apparatus, be light and of low cost have been increasing recently. For electric power equipment such as bushings, simple structures with short assembly times are also demanded. Since conventional bushings are made of porcelain and contain oil for internal electrical insulation, they are very heavy, do not withstand earthquakes well, and pose risks of environmental pollution if broken. As described in News from Japan in the January/February 2013 issue [1], polymer-housed electric apparatus showed much better antiseismic performance than porcelain-housed apparatus in two big earthquakes that hit Japan in July 2007 and in March 2011. Consequently, demands from Japanese power utility companies for bushings with strong seismic resistance have increased sharply. In response, SWCC Showa Cable Systems Co. Ltd., Tokyo, has developed prefabricated polymer-insulated bushings and cable sealing ends.

전력퓨즈의 열화현상 개선에 관한 연구

본 논문은 변압기 1차측에 설치된 전력퓨즈의 열화현상을 진단하고 문제점을 해결하고자 한다. 전력퓨즈의 열화현상은 퓨즈 엘리멘트에 반복하여 흐르는 평상전류에 의해 오동작하는 주된 원인이 된다. 따라서 전력퓨즈 전, 후단과 옥내 변전실내 전력기기의 온도변화와 전력퓨즈 열화현상의 관계를 규명하여, 열화현상의 원인을 제거하여 부하설비의 증설을 조사하여 전력퓨즈를 재산정하였다. 변압기는 개선전과 비교하여 평균 $6[^{\circ}C]$ 가량 하락하였고, 전선로의 온도는 $7{\sim}8[^{\circ}C]$ 가량 개선되었다. 전력용 콘덴서와 직렬리액터는 실내온도 및 기기동조화와 관계되어 $2{\sim}3[^{\circ}C]$ 높은 상태 유지됨을 알수 있었다. 연구대상인 전력퓨즈 3상간 온도차는 $0.5{\sim}1.0[^{\circ}C]$ 로 안정화 됨을 보였다. 이에 따라 옥내 변전실내의 환경적인 전력기기간의 온도발생요인을 제거하여 전력퓨즈의 열화 및 온도상승을 억제할 수 있음을 제안 하였다. 【This paper aims to solve the problem deterioration of power fuses. The deterioration of a power fuse is a cause of failure misoperation by a normal current flowing reduplicatively to fuse the element. An extension survey of a load feature rerating power fuse examined the power fuse deterioration removal, the cause of the deterioration of the power fuse, the front-after, and the thermal variation of the inside transformer room electric power equipment. The transformer showed an average improvement of $6[^{\circ}C]$ . The temperature of the electrical line showed $7{\sim}8[^{\circ}C]$ improvement. The static condenser and direct reactor was $2{\sim}3[^{\circ}C]$ high-state maintenance the temperature and equipment syntonization relationship. In the subject of study $0.5{\sim}1.0[^{\circ}C]$ stabilizing three phase power fuse temperature differential was. Suggestion in the transformer room environment power equipment between the cause temperature happen elimination to deterioration of power fuse and temperature rise control.】

End-of-life assessment of electric power equipment allowing for non-constant hazard rate – Application to circuit breakers

A statistical methodology is proposed for end-of-life studies of aging populations of electric power equipment. As an example, this methodology is applied to Hydro-Québec’s 120- and 161-kV minimum-oil circuit breakers. Non-parametric and parametric statistical methods allowing for a non-constant hazard rate are used to estimate apparatus survival as a function of time since commissioning or manufacturing. This function is then used to estimate hazard rate, mean residual life, mission reliability and life expectancy. This information provides valuable insight for end-of-life management of electric power equipment, which is still usually based on hazard rate estimates independent of age.

Feature Extraction and Classification of Electric Power Equipment Images based on Corner Invariant Moments

Feature extraction and accurate classification of electric power equipment, help to improve the automation and intelligent level of power system management. Aiming at the problems that applying Hu invariant moments to extract image feature computes large and applying corner vector to match has too dimensions, this paper presented Harris corner invariant moments algorithm. This algorithm only calculates corner coordinates other than the entire image coordinates, so can change the point feature into feature vectors, and reduce the corner matching dimensions. Combined with the SVM (Support Vector Machine) classification method, we conducted a classification for a large number of electrical equipment images, and the result shows that using Harris corner invariant moments algorithm to extract invariant moments, and classifying by these invariant moments can achieve better classification accuracy. DOI : http://dx.doi.org/10.11591/telkomnika.v12i6.1422

Influence of Perforated Metal Plate on Pressure Rise and Energy Flow due to Internal Arcing in a Container With a Pressure-Relief Opening

Internal arc tests and computational fluid dynamics' calculations regarding the effect of a perforated metal plate (absorber) on pressure rise and propagation in a container with a pressure-relief opening are carried out. In the calculations, the perforated metal plate is simply considered as a medium of gas-flow resistance and a heat sink/conductor. The pressure development at different locations within the container, and the maximum pressure rise PMAX and the mean pressure value PMEAN are measured and calculated by changing the aperture ratio RAP of the perforated metal plate and the cross-sectional area AOP of the pressure-relief opening. In addition, the energy flow density EFOP and the total energy flow QOP at the opening depending on RAP and AOP are estimated. From the following investigations, it is necessary to consider the dependence of the ratio PMAX to PMEAN on the value of RAP, and the dependence of EFOP and QOP on the value of AOP, when designing electric power equipment.

Local heating of electrical pathways of power electrical equipment under emergency conditions and overcurrents

Based on the positions of classical and quantum electrodynamics, this paper shows that when a direct, alternating or pulsed current of high density (100 A/mm2 or more) flows in emergency situations through metal electrical pathways of power electrical equipment, such electrical pathways in areas of their narrow “hot” longitudinal sections may experience intense local heating. It was found that Joule heating temperatures, which occur in this situation on the “hot” longitudinal sections of the electrical pathways due to periodic localization of electrons on them, are higher by up to 3.5 times than the corresponding temperatures on their adjacent “cold” sections and may lead to electrothermal destruction of these electrical pathways. Experiments confirmed the main results of calculations.

Contact-based corrosion mechanism leading to copper sulphide deposition on insulating paper used in oil-immersed electrical power equipment

XPS and EDX were used to study CuxS deposition in Kraft insulating paper obtained from ageing paper samples in contact with a copper sheet, in mineral oil containing dibenzyl disulphide (DBDS). Qualitative and quantitative evidence of CuxS were obtained from bulk and surface analyses of insulating paper provided by the different depth resolution of the techniques used. The influence of [DBDS], oxygen, time, and Cu-paper contact upon the formation and mobilisation of CuxS were studied. A contact-based mechanism to explain CuxS contamination on paper and its displacement was proposed. The role of O2 in enhancing CuxS displacement was also investigated.

Short-Range Wireless Technology in Electric Power Equipment Application

In this paper, short-range communication technology, power transmission or for certain control devices, has developed an easy to monitor and control the local portable handheld device, meet people based portable monitoring requirements, first, short-range wireless communication module design, followed by the portable handheld device and GIS controller design, and ultimately lower PC and wireless communication between machines. To achieve the purpose of the portable control.