医用电气设备第2-37部分新标准内容变化

GB 9706.237-2020标准已定稿,其内容较GB 9706.9-2008而言,新增和修改了一些内容,同时也删除了一些附录内容。本文主要对新版标准的变化内容进行了汇总,希望能够给相关人员理解标准提供帮助。

电气设备在线监测与故障诊断技术现状和前景分析

分析电气设备在线监测与故障诊断技术对保证用电安全有重要意义,文章从实践入手,对其所存在的问题进行探讨,并提出解决措施。同时,研究了状态维修和在线监测技术两者之间的相关性,作为电网安全运行的重要技术之一,在线监测电气设备状态和诊断技术在应用前景上比较乐观。

基于结构-设备动力相互作用的户内式变电站抗震设计优化

结合黄屯110 kV变电站生产综合楼设计实例,在结构-电气设备复合体系中考虑二者相互动力作用,分析复合体系在大震弹塑性阶段的地震响应,并与不考虑相互作用的计算模型比较分析。分析结果表明,在大震作用下,电气设备参与整个复合体系的动力反应,使主结构的地震响应变大,同时电气设备本身的动力作用也变大,如仍采用传统的等效荷载法设计是偏不安全的,最后给出主结构和电气设备抗震设计的合理建议和优化措施。

Research on Influence of Electromagnetic Interference on X-Ray Digital Detection

X-ray digital imaging technology has found wide application owing to its advantages of real-time, visualization and rapid imaging. In substations the substantial electromagnetic interference has some influence on the live detection by the X-ray digital imaging technology, hindering the promotion of the technology in the detection of electric equipment. Based on a large number of field tests, the author carded out a series of researches on electromagnetic interference protection measures, image de-noising, and image enhancement algorithms.

Prediction Model for Cooling of an Electrical Unit with Time-Dependent Heat Generation

The satisfactory performance of electrical equipments depends on their operating temperature. In order to maintain these devices within the safe temperature limits, an effective cooling is needed. High heat transfer rate of compact in size and reliable operation are the challenges of a thermal design engineer of electronic equipment. Then, it has been simulated the transient a three-dimensional model to study the heating phenomenon with two assumption values of heat generation. To control for the working of this equipment, cooling process was modeled by choosing one from different cooling technique. Constant low speed fan at one direction of air flow was used for cooling to predict the reducing of heating temperature through working of this equipment. Numerical Solution of finite difference time domain method （FDTD） has been utilized to simulate the temporal and spatial temperature profiles through two processes, which would minimize the solution errors.

GB3836.1～2-2000《爆炸性气体环境用电气设备》与GB3836.1～2-83《爆炸性环境用防爆电气设备》的差异

详细论述了GB3836.1-2000《爆炸性气体环境用电气设备第1部分通用要求》与GB3836.1-83《爆炸性环境用防爆电气设备通用要求》,以及GB3836.2-2000《爆炸性气体环境用电气设备第2部分隔爆型"d"》标准与GB3836.2-83《爆炸性环境用防爆电气设备隔爆型电气设备"d"》的差异。对标准动词"应"与"须"、"不应"与"不得"提出了自己的认识。

Non-local Consciousness Influence to Physical Sensors： Experimental Data

Experimental approach to investigation of NLCI （Non-local Consciousness Influence） effects is based on sensors of different design, and most of it based on transitional effects in gas-discharge plasma with several quasi-stable states is also presented. Computerized device for detecting NLCI is based on commercially available Gas Discharge Camera （www.ktispb.ru） and allows following time dynamics of several sensors in NLCI conditions. The typical sensors are： water, air, earth, and wood, this instrument was named ＂The 5th Element＂. Readings are taken continuously by special software every five or ten seconds in automatic mode. Sensitivity of the device was tested by detecting the influence of total sun eclipse in Siberia in 2008 and by detecting sunrise and sunset. Several experimental modalities have been developed： （1） directed NLCI of a person; （2） directed NLCI of a group of people; and （3） non-directed NLCI of a group of people. Experiments during many years demonstrated efficiency of the developed approach.

Partial Discharge Measurement of OCP-Tapes in Rotating Electrical Machines

Nowadays, PD （partial discharge） measurements are a crucial part of the preventive maintenance of electrical equipment within high voltage engineering. Especially for electrical machines, both the supplier and the user are interested in the results of PD measurements. However, PDs hardly represent the cause of the failure, more likely they are claimed as the outcome of a failure. This paper deals with the insulation of a 6 kV electrical machine, whereas PD measurements were carried out at a single stator from wound coils. During manufacturing, these coils were equipped with different materials for the OCP （outer corona protection）. Using different PD measurement systems and different bandwidths, investigations of the PD behavior of the coils were carried out. Additionally, the surface resistivity of the corona protection was determined. As a result, conclusions for the correlations between the resistance of the OCP as well as the PD behavior are stated. Furthermore, the influence of using different measurement systems, different measuring circuits, and different bandwidths is shown.

Electromagnetic Fields and Induced Voltages on Underground Pipeline in the Vicinity of AC Traction System

Various regulations, aimed at the protection of human beings and electrical equipment against possible adverse effects resulting from exposure to electromagnetic fields, have been issued in many countries. Most of them are based on safety guidelines published by international expert groups. In this paper, electric and magnetic fields are calculated in the vicinity of 25 kV traction line supplying railway traction systems. Calculation results are compared to exposure limits specified by safety guidelines and regulations. Possible countermeasures for reduction of electromagnetic fields are proposed. Also, this paper presents a method for calculation of the induced voltages to an underground gas pipeline from a neighbouring 25 kV electric traction overhead line in case of short circuit. Calculations are performed with EMTP-ATP software. Possible countermeasures for reduction of induced voltages are proposed.

Utilization of Data Communication according to the IEC61850 Standard for Nuclear Power Plant Electrical Equipment Testing

This paper deals with an integration of directly measured electrical parameters with data acquired by data communication from protections and terminals into an advanced monitoring system. Based on the periodic test, the authors of this paper present the possibility of an extended evaluation and more accurate analysis of transient and failure events. For periodical testing, as implemented during the commissioning of power plants in the Czech Republic, a monitoring system of electrical equipment has been used, to record the courses of important electrical parameters and thus, proving the proper functioning of complex technological systems in various operation modes. Data from monitoring system were used to prove the successful results of the test or as a base data for further analysis of failures. The monitoring system has proved itself as a very useful device also when recording unexpected failure events, the cause of which was very quickly and accurately detected by the follow-up analysis. Initially, only the voltage and current data from measuring transformers, analogue transducers and contact relays were used as input data for the monitoring system. After the implementation of new digital protection technology and controlling terminals with inner data recorder, the data from digital devices could be also utilized for the monitoring system.

Refreshing File Aggregate of Distributed Data Warehouse in Sets of Electric Apparatus

Integrating heterogeneous data sources is a precondition to share data for enterprises. Highly-efficient data updating can both save system expenses, and offer real-time data. It is one of the hot issues to modify data rapidly in the pre-processing area of the data warehouse. An extract transform loading design is proposed based on a new data algorithm called Diff-Match,which is developed by utilizing mode matching and data-filtering technology. It can accelerate data renewal, filter the heterogeneous data, and seek out different sets of data. Its efficiency has been proved by its successful application in an enterprise of electric apparatus groups.

Design of a Special PLC for Garbage Truck

A special PLC is designed for the control system of garbage truck,based on the feature and applications of vehicular electrical device.The purpose is developing a kind of mature products to control the hydraulic system.The general design plans are described,in detail,and the design points are analyzed and summarized.

System Validation Tests for an SOFC Power System at INER

This research presents the results of system validation tests for an SOFC power system. In the study, the system was heated up without electric device, i.e., the fuel providing the required thermal energy through an integrated BOP （balance of plant）. The ex-situ experiments, without an SOFC stack installed in the system, were fast conducted to investigate the operability of a BOP apparatus. It was found that the BOP possessed high conversion rates for both steam reforming and water gas shift reactions. The total fuel concentration of hydrogen and carbon monoxide from the reformer was around 91.2%. The system validation tests showed that, with the natural gas as fuel, the output power from the stack reached to 1,060 W, while the fuel utilization efficiency and electrical efficiency were 67.16% and 45.0%, respectively. A steady 600-hour system operation test was carried out at an average system temperature of 694℃. Of which, a 36-cell stack was employed for the test. Meanwhile, the current, voltage and output power were 26 A, 32.3 V and 840 W, respectively, and its electrical efficiency was around 33.4%.

A Comparison of Domestic and Foreign Seismic Fortification Standards for Electrical Equipment

It is of great significance to make comparative analyses of seismic fortification criteria at home and abroad for improving the anti-seismic capability of electrical equipment and revising the relevant national standards.A brief overview of American,Japanese,IEC standards and Chinese seismic design codes for electrical equipment is presented.Differences between these seismic fortification standards of electrical equipment are compared and analyzed in respect of the goal and level of seismic fortification and the seismic design spectrum.The advantages and disadvantages of Chinese standards are pointed out.Through learning from foreign experience on the determination of seismic fortification standards,recommendations are made for the improvement and revision of Chinese seismic fortification standards for electrical equipment.

Analysis on Economic Performance of Electrical Equipment Industry in 2010

In this paper the analysis is presented on the economic performance of the electrical equipment industry in 2010.Substantial increase was seen in both the economic aggregate indices such as production and sales,and economic efficiency indices such as profits.Increase of indices that reflect foreign trade situation of the industry,such as import volume,export volume,gross import and export volume,and export delivery volume were prominent in particular.The industry has completely stepped out of the "negative growth" predicament in 2009,comprehensively outperformed the level in 2008,and recovered true growth.The economic situation of the electrical equipment industry in 2011 is also predicted in this paper.

Characteristic Period Value of the Seismic Design Response Spectrum of UHV Electrical Equipment

Characteristic period is an important parameter of the seismic design response spectrum. There is important theoretical significance and engineering application value to the study of the characteristic period of seismic design response spectrum of ultra high voltage （UHV） electrical equipment. In this paper, 1448 horizontal earthquake records within the world scope including the United States and Japan for Site Class m were analyzed. Results show that both magnitude and epicentral distance have great influence on the characteristic period. About 80 % of characteristic periods of strong earthquake records are about 0. 9s. Statistical analysis was conducted on the seismic hazard assessment results of 312 projects of China in recent years, and it is found that about 70 % of characteristic periods are about 0. 9s. Combined with the related code comparison and analysis, it is suggested that the characteristic period of the seismic design response spectrmn of UHV electrical equipment should select 0. 9s in order to effectively guarantee the seismic safety of UHV electrical equipment.

Study on Negative Impact of Harmonic Components on Sensitive Electric Equipment

Distribution systems operators are often confronted with declined power quality, which can cause substantial economical losses. The problem analyzed in paper concerns thyristor controlled direct current motor used for ski-lift in ski resort as a source of disturbances with negative impact on sensitive electric equipment, which is then unable to operate correctly. To solve mentioned problems, series of measurements of voltage quality parameters were carried out according to the respective valid standards. Crucial power quality parameters necessary for parallel power active filter design were then analyzed. Power active filter compensates power factor and filters characteristic current harmonics. After power active filter was put into operation, power quality problems were eliminated. Payback period is estimated up to four years.

An Advanced Teaching Lab for the Setting up of an Islanded Production Unit

The present paper addresses an advanced teaching lab consisting of setting up an islanded production unit. This teaching lab takes place in the very last semester at master level for students in electrical engineering with energy specialization. The purpose of this teaching lab is to combine knowledge learned in different areas such as power electronics, control, electrical machines and networks, and make use of all of them in practice. The present paper describes in detail the different steps followed by the student to set up an islanded production unit.

Methods and Results of Assessment of the Pulse Electrical Disturbances Influence on. Digital Devices Functioning

Two methods of calculating the parameters and characterizing the degree of pulse electrical disturbances influence on digital devices functioning, both analytical and numerical, are considered here. The analytical method permits one to assess the error occurrence probability in transmitting the data packets considering the dependence on the signal pulses energies-to-pulse disturbances energies ratio and the disturbances repetition frequency-to-data transmission rate ratio and also the dependence on the bits quantity in the packet. The numerical method allows one to assess the specific effect of the repetitive pulse disturbance influence on the digital devices functioning （the number of errors in transmitted data packets, transmission rate, etc.） depending on such factors as the repetition frequency, the disturbance waveform and duration, the mode of data coding, etc..

Pressure Rise in Electrical Installations due to Internal Arcing in CO2 as Insulating Gas

Internal arcs cause a rapid increase in pressure in electrical installations. The type of insulation gas has influence on pressure development. Typically SF6 is used incompact metal-clad switchgear, however, it has a high global warming potential. Because of this, the replacement of SF6 by alternative gases such as CO2 is under discussion. The pressure developments in a closed vessel filled with air, SF6 and CO2 are measured and compared. During internal arcing in gas-insulated switchgear, overpressure causes a rupture of a burst plate and hot gas escapes into the surrounding room mixing with air. In order to predict the pressure development in electrical installations reliably, the portion of energy causing pressure rise, arc voltage as well as reliable gas data i.e., thermodynamic and transport properties, must be known in a wide range of pressure and temperature. These data are up to now not available for CO2/air mixtures. The thermodynamic properties are directly calculated from the number densities, internal partition functions and enthalpies of formation. The transport coefficients are deduced using the Chapman-Enskog method. Comparing measured and calculated pressure developments in a test arrangement demonstrates the quality of the calculation approach.