High Voltage Area Research Articles

Assessment of Hazards and Safety Practices in Food and Beverage Industry in Nigeria

The assessment of safety hazards is fundamental to an effective risk management in any industry. Food and beverage production involves a variety of industrial processes with associated hazards. Effective safety practices are used to reduce workplace hazards and promote safety in the work environment. This paper evaluated safety hazards and safety practices in the food and beverage industry (FBI) in South-South, Nigeria. A structured questionnaire designed in accordance with World Health Organization standard was administered to a total of 144 workers, out of which 134 (93.0%) were completed and returned. The questionnaire was fashioned to extract information on types of hazards, awareness of safety hazards, implementation of hazards and risks control measures and the effectiveness of safety hazards and risk management programmes in the food and beverage industry. A modified four-point Likert Scale was used to analyze and evaluate the questionnaire. A Proportional Importance Index (PII) was used to rank each factor variable in the questionnaire. The study identified the major hazards in the FBI as working at height (with PII = 3.3, respondents = 91%); high voltage areas (PII = 3.1 and respondents = 90%), loud noise (PII = 3.0, respondents = 80%), machines and equipment vibration (PII = 2.8, respondents = 69%) and faulty machines and equipment (PII = 2.7, respondents = 65%). The level of awareness on safety hazards amongst the workers was statistically significant (p < 0.05, 95%CI; PII = 3.1 - 3.6). The outcome of intervention showed that FBI-2 improved from 79.62% to 96.82%, FBI-3 improved from 89.81% to 96.18%, FBI-4 improved from 78.34% to 95.54% on worker’s knowledge on the assessment of hazards and risk in the FBIs. There was effective implementation of safety hazards and risks management programmes and controls in the FBI. Administrative control measures are used to reduce hazards and workers make adequate use of personnel protective equipment. There is need to evaluate the risks associated with identified high ranking hazards and develop a risk management framework for the industry based on ISO 31000 and other relevant safety regulations and guidelines.

1.38kV Merged Pin Schottky Rectifier for High Power Device Applications

In this paper, we have proposed a modified version of junction barrier schottky diode (JBS) with fused trench structure to enhance electrical properties. The device has an increased current density, low forward voltage drop, high breakdown voltage and large schottky contact area as compared to previous merged pin-junction barrier schottky diode.4H-SiC is used as a substrate and device is purely simulation based. To carry out simulation work Silvaco TCAD(ATLAS) is used. The simulated device has current density of 110 A/cm2 with schottky region having height of 2.5 μm and at a forward voltage drop of 2.5 V. The proposed device has more number of schottky contacts than the previous devices and it reduces the forward voltage drop by 20% at current density of 140 A/cm2. The output capacitance of this device, common JBS and earlier merged pin schottky diode are almost same. Moreover, the forward and reverse features of device are studied at room temperature (25 °C) as well as at higher temperatures.

Electric Field Exposure Assessments and a Novel Control Method for Buildings Installed Nearby High-Voltage Lines.

This essay presents a review of new methods for electric field value assessment in high-voltage areas. For buildings that are placed near high-voltage transmission line corridor, two main scenarios are modeled using finite element method. A new approach to reduce electric field value is also simulated and the results are discussed in detail. The results are compared to related standards values. In some cases the improvement rate exceeds 65%.

PEMANFAATAN RADIASI ENERGI TEGANGAN 150 KV UNTUK LAMPU LED PENERANGAN JALAN

WHO (World Health Organization) concludes that not much effect is caused by electric field up to 20 kV / m in humans. WHO standard also mentions that humans will not be affected by the magnetic field under 100 micro tesla and that the electric field will affect the human body with a maximum standard of 5,000 volts per meter. In this study did not discuss about the effect of high voltage radiation SUTT (High Voltage Air Channel) with human health. The research will focus on energy utilization of SUTT radiation. The combination of electric field and magnetic field on SUTT (70-150KV) can generate electromagnetic (EM) and radiation waves, which are expected to be converted to turn on street lights around the location of high voltage areas or into other forms.The design of this prototype works like an antenna in general that captures electromagnetic signals and converts them into AC waves. With a capacitor that can store the potential energy of AC and Schottky diode waves created specifically for low frequency waves, make the current into one direction (DC). From the research results obtained the current generated from the radiation is very small even though the voltage is big enough.

Study on the Cauer Thermal Network Model of Press Pack IGBTs

Press Pack IGBTs (PP IGBTs) has been gradually applied in the high voltage and high current areas, for its high power density, double side cooling and high reliability. The cauer thermal network model of PP IGBTs is proposed based on the boundary effect according to heat spreading angle in this paper, and the difference between the IGBT and FRD chips is considered in this model. The thermal contact resistance among multi-layers within PP IGBTs, which is calculated and corrected by the experiment, is also included in this model. The finite element method (FEM) model is used to verify the accuracy of the cauer model, because the accurate measurement of the junction to case thermal resistance of PP IGBTs is extremely difficult. The thermal characteristic of PP IGBTs under different clamping force can be acquired through the cauer thermal model. It has significant influence on the thermal resistance optimization, as the thermal resistance percentage of the components in PP IGBTs can be obtained from the cauer thermal model.

Battery thermal management system for electric vehicle using heat pipes

Thermal management of battery systems in electric vehicles is critical for maintaining energy storage capacity, driving range, cell longevity and system safety. In this paper, heat pipe based thermal management system for high power battery, with eight prismatic cells, has been proposed, designed and tested for heat load up to 400 W. The heat pipe system consists of two parts: heat pipe cooling plates to extract heat from the individual prismatic cells of the battery module, and remote heat transfer heat pipes to transport heat from the module to liquid cooled cold plates located 300 mm away. As compared to a conventional liquid cooled system, two-phase heat pipe based thermal control will provide better cell/module temperature uniformity, less complicated design and a safer system (no leakage issues in high voltage areas). Modeling of the complete system was done based on two-phase analysis for the heat pipe portion, and single phase analysis for the cold plate portion. The system manufacturing and evaluation method has been covered in detail. Based on controlled experimentation using a dummy battery module, it was estimated that the proposed system is able to successfully dissipate 50 W heat load from each cell while keeping their temperature below the given 55 °C limit using water coolant with a 25 °C inlet temperature and 1 lit/min flow rate.

THE MECHANISM AND EXPERIMENTAL STUDY ON THE INTERFERENCE OF HIGH VOLTAGE LINES TO NAVIGATION SYSTEM

This essay conducts the mechanism analysis and experimental study on the interference of high voltage lines to the navigation system of UAV and shows that the essence of the interference is that air becomes corona plasma after the ionization under high voltage. In addition, when GPS signals pass through this area, some frequency channel will be absorbed. Therefore, the propagation of electromagnetic waves is prevented. The UAV tries to get GPS positioning signal by flying through high voltage area in a low height, resulting in the loss of GPS signal received by the navigation system. Through the measurement and comparison of the electromagnetic wave spectrum traveled through corona plasma, the corona plasma’s absorbing of electromagnetic wave is observed.

PEMANFAATAN RADIASI ENERGI TEGANGAN 150 KV UNTUK LAMPU LED PENERANGAN JALAN

WHO (World Health Organization) concludes that not much effect is caused by electric field up to 20 kV / m in humans. WHO standard also mentions that humans will not be affected by the magnetic field under 100 micro tesla and that the electric field will affect the human body with a maximum standard of 5,000 volts per meter. In this study did not discuss about the effect of high voltage radiation SUTT (High Voltage Air Channel) with human health. The research will focus on energy utilization of SUTT radiation. The combination of electric field and magnetic field on SUTT (70-150KV) can generate electromagnetic (EM) and radiation waves, which are expected to be converted to turn on street lights around the location of high voltage areas or into other forms. The design of this prototype works like an antenna in general that captures electromagnetic signals and converts them into AC waves. With a capacitor that can store the potential energy of AC and Schottky diode waves created specifically for low frequency waves, make the current into one direction (DC). From the research results obtained the current generated from the radiation is very small even though the voltage is big enough.Keywords : Radiance Energy, Joule Thief, and LED Module.

Application of the Green’s Function in Attenuation Factor to Solve the Status of Human Health on the Earth

The activity in the high-voltage environment is at risk of being injured by electric shock. The safety of personnel in and around electric power installations has been a prime concern. Specifically, this safety is generally in terms of the allowable touch and step voltages. These voltages are related to the ground resistance of human foot. In order to increase the safety of personnel, a high resistivity surface layer of gravel normally exists in the substation switchyards or other high-voltage areas. The thickness of this layer will affect the calculation of the ground resistance of human foot. Among them, the electromagnetic field and humidity factors are also considered in this paper. As a result, the surface layer of gravel can be used to reduce the earthing resistance of human foot. The equivalent model of human foot was modeled by the circular plate conductor in the past, which considered the beauty of the environment. Most of the transmission lines are in the surface, so the transmission line generated by the discrete current will affect the earthing resistance estimation. Thus, the proposed paper will consider the composition of the Green’s function which is the mathematical calculus popularized by the basic theorem of calculus. On the other hand, the damp ingredients and temperatures on the surface will also be considered in this paper. This paper researches into the proposed method for estimating the ground resistance of human foot and proposes an equivalent model for calculating the earthing resistance of human foot. A comparison of the method is also shown in this paper.

An Investigation of Grounding Resistance Estimation of Human Body by Attenuation Coefficient

It is dangerous when human are working in and around the high voltage environments. The safety of personnel in and around electric power the installations has been a prime concern. Specifically, this safety is generally in terms of the allowable touch and step voltages. These voltages are related to the ground resistance of human foot. In order to increase the safety of personnel, a high resistivity surface layer of gravel is normally existed in the substation switchyards or other high voltage areas. The thickness of this layer will affect the calculation of the ground resistance of human foot. Among them, the electromagnetic field factors are also considered in this paper. As a result, the surface layer of gravel can be used to reduce the ground resistance of human foot. The equivalent model of human foot was modeled by the circular plate conductor in the past. This paper investigates the present methods for estimating the ground resistance of human foot and proposes an equivalent model for calculating the ground resistance of human foot. A comparison of the proposed model and present methods is also shown in this paper.

Field emission characteristics of nano-diamond cathode surface by graphitization pretreatment

Cathode samples of nano-diamond by graphitization pretreatment with different temperatures were fabricated by electrophoresis, then the structures and morphologies of the cathode samples were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD), and the field emission tests were conducted. The effects of graphitization pretreatment on the field emission characteristics of nano-diamond cathode surface on titanium substrate are studied. The results indicate that the surface morphologies of nano-diamond cathode samples after graphitization pretreatment change a lot, and the field emission characteristics in low-voltage area are improved obviously. However, in high-voltage area, the curve distortion happens, and it doesn’t conform the mechanism of field emission characteristics.

Delay Dependent Robust Load Frequency Control Synthesis in AC-DC Interconnected Power System Using Genetically Optimized Fuzzy Logic Controller

The load-frequency control (LFC) is used to restore the balance between load and generation in each control area by means of speed control. The objective of LFC is to minimize the transient deviations and steady state error to zero in advance. Conventionally, the membership functions and control rules of fuzzy logic control are obtained by trial and error method are experience of designers. To overcome this problem this paper focuses on a new optimization technique of a fuzzy logic controller based load frequency controller (LFC) tuned by genetic algorithm (GA) in co-ordination with frequency controllable HVDC links. In this proposed system Area 1–2, Area 2–3 are connected by frequency controllable High Voltage Direct Current transmission links and Area 2–3 is connected by normal AC tie-line. By using the system interconnections as the HVDC link, the tie-line power modulation of HVDC link through interconnections is possible. The advantage of incorporating time delays is important for satisfactory dynamical responses. The HVDC transmission link is to transfer power over long distance without any frequency deviation.

Using WAMS for HVDC Control

Abstract: The paper presents how a combination of two progressive technologies - high-voltage direct current (HVDC) and wide area monitoring system (WAMS), can contribute towards secure power system operation and enable flexible power flows control. A new control algorithm based on WAMS for HVDC connection has been proposed and tested on a dynamic model of the future Central East European region.

Modification of the Centre Differential Gearbox

The paper deals with the optimization of the centre differential heavy truck without a wheel reductions. Under optimization in this case means customizing cabinet differential type designed for easy gear to withstand a heavy load of new gear. Critical structural adjustment of high-voltage areas must be such as to reduce tensions. The basis for this optimization is the results of task solution by finite element method (FEM).

High Temperature Baking Test and Study on Axial Insulation Breaks

Axial insulation breaks are needed in ITER superconducting magnet system, which are used for separation of high voltage area from grounded cooling pipes system. To determine the maximum safe temperature that the insulating break can withstand without damage, such as preventing damage by overheating during welding of the insulating breaks to the helium cooling pipes for the superconducting magnets and high temperature baking to remove moisture, the glass transition temperature was tested by using the dynamic mechanical analysis with the standard sample made from epoxy resin. Furthermore, the high temperature baking test of axial insulation break was performed, further helium tight test and high voltage tests indicate the baked insulation break is in good condition.

Features of cooling dynamics in a high-voltage electron cooling system of the COSY

An electron cooler designed at the Budker Institute of Nuclear Physics for the Cooler Synchrotron COSY (Juelich, Germany) has been put into operation. The aim of this cooling device is to prevent the beam scattering on an internal target up to the maximal energy of the transmitted beam. The device provides cooling in a strong longitudinal magnetic field generated in a high-voltage area. The motion of electrons in the magnetic field considerably improves the kinetics of electron—ion collisions, because their transverse velocity component (which is very high as a rule) does not participate in the process. First experiments on electron beam cooling on energy 200 MeV were made in 2013. Early in 2014, sessions on electron beam cooling to 200, 350, 580, and 1660 MeV were carried out. In other experiments, deuterium beams were cooled down. Experimental data for the cooling time are compared with the respective theoretical predictions. These results may be used in cooling projects for the Nuclotron-based Ion Collider fAcility (NICA), Joint Institute for Nuclear Research, Dubna, Russia, and the Facility for Antiproton and Ion Research (FAIR), Darmstadt, Germany.

Geometric Optimization of the Differential Gearbox

The paper discusses optimizing of centre differential heavy truck wheel without reductions. Under optimization in this case is meant the differential type customizing cabinet designed for easy gear to withstand heavy load of a new gear. Critical structural adjustment of high-voltage areas must be such that tensions are reduced. The basis for this optimization is the result of task solution by finite element method.

A High-Precision Binocular Measurement System

The system uses three-dimensional measurement of binocular vision theory, through optical, mechanical, computer and other aspects of the technology to measure the target without contact, and up to a certain precision. In the high-voltage area, high-altitude target,and the target which is not easy to touch, there is a unique measure advantage. Binocular stereo vision is based on the principle of parallax and using imaging devices from different locations to obtain two images of the measured object and obtain three dimensional geometric of target by positional deviation between corresponding points in computer image. Binocular stereo currently used in four areas: robot navigation, micro operating system parameter detection, three-dimensional measurements and virtual reality. In addition, the system not only to measure the length of the distant object, the system can also be used to measure the width, surface area, height and tilt angle. As the tip of an optical imaging technology this system has a broad application prospects in the future.

Use N+ Buried Layer to Design a Low On-Resistance VDMOS

A novel structure of a VDMOS in reducing on-resistance is proposed and experimentally demonstrated with a 200V N-channel VDMOS. With this structure, the on-resistance value of the VDMOS is reduced by 19.6% than that of a traditional VDMOS structure as the breakdown voltage almost maintained the same value, and there is only one additional mask in processing this new structure VDMOS, which is easily fabricated. By TCAD tool, the specific on-resistance value will reduce by 23%, and the value by 33% will be realized when the device is fabricated in three epitaxies and four buried layers. The novel structure can be widely used in high-voltage VDMOS and BCD areas.

High Voltage Testing of ITER Prototype Axial Breaks

Axial insulation breaks are needed in forced cooled cryogenic high voltage devices like fusion magnets for the separation of the high voltage area from the grounded pipe system. For the verification of the ITER requirement compatibility, a special type test series was defined for a set of cryogenic and room temperature prototype axial breaks. This paper gives an overview of high voltage type tests performed on a set of 5 cryogenic breaks and 3 room temperature breaks designed and manufactured by Babcock Noell. Direct voltage, alternating voltage, and impulse voltage tests were performed to reproduce in an economic way the different voltage loads during current operation, fast discharge, and fault events. In addition, for 2 cryogenic breaks, Paschen tightness was demonstrated at 35 kV DC.