Papers by Keyword: Voltage

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Authors: Wen Xuan Cai, Ke Wu Zou, Hai Bo Qi
Abstract: A large number of wind farms have been built in recent years, it is growing that the wind generating sets share of the total. On the other side, as the controllability of wind generating set is far weaker than the thermal generator set or hydro electric generating set. It leads to many problems for the power grid, such as voltage fluctuation or flicker generated in the process of continued operating or switching operation. It will bring a bad influence on power quality of local grid. Combined with practical conditions in Hebei Hongfeng wind farm, in this paper aiming at wind generating set output fluctuation, the reactive power compensation and the grid stability, mainly setting out from several aspects, analyzes the main reasons of grid voltage fluctuation or flicker caused by wind power generation. It is also analyzed that lowering the grid voltage instability.
Authors: Nirdesh Ojha, Florian Zeller, Claas Mueller, Holger Reinecke
Abstract: With the help of an Assisting Electrode (AE), non-conductive ceramics can be machined using Electrical Discharge Machining (EDM) process. The AE helps start the EDM process and the intrinsic conductive layer (ICL) ensures that the electrical contact between the workpiece and the generator is maintained. However, the understanding of EDM process of non-conductive ceramics is limited due to the typical characteristic of the process: the geometric dimension of the discharge region is limited to few micrometers and the duration of the dielectric discharge is in the range of few microseconds making it difficult to directly observe the spark and the associated crater formation phenomenon. Analyzing the electrical signals during the EDM process could provide an insight of the process. This paper presents a study on analyzing the electric pulses occurring during the EDM process of a conductive workpiece (copper) and a non-conductive workpiece (Si3N4 ceramics). Typical pulses occurring during the EDM of a metal and a non-conductive ceramics are identified with the signal recorded at a sampling rate of 2.5 GS/s. Sampling rate of 25 MS/s is used to monitor the pulses occurring while machining a hole with depth of 1 mm. The pulses during EDM of non-conductive materials are significantly different than those during EDM of metals. Four most outstanding differences have been identified in terms of the ringing behavior of the voltage signal, the recharge time required to reach the set value of open voltage, the presence of the reverse current and the value of the peak current detected in case of Si3N4. The pulses monitored with lower sampling frequency was characterized and discriminated into sparks, arcs and short circuits. The percentage of the discriminated pulses for varying machining depth of the test structure has been presented.
Authors: Shan Feng Li, Lei Yang
Abstract: Measurement and control system plays a gatekeeper and director role in industrial production. It obtains various parameters from the production site, in order to meet the needs of production, improve quality, ensure safety in production. Distributed measurement and control systems scalability, inexpensive cost and other factors have been widely used. This paper mainly discusses a distributed measurement and control system which based on STC89C52 MCU, RS485 bus, 18B20 temperature components and ADS7822 voltage acquisition components with a main control terminal and three nodes, through RS485 communications. The main control terminal has keyboard and LCD1602 displayer, which can read each node state. Each node refers to one of the measurement and control items below (temperature measurement, current or voltage measurement, switch input measurement and switch output control).
Authors: Wei Hua Chen, Yan Wei Chen
Abstract: Voltage is a key factor not only to power system but also to user. Keep voltage steady is a hot point for researching. Paper proposed keeping steady voltage and improving power quality by using intelligent auto voltage control system. This method is based on the existing power system software and hardware platforms. It is of the advantages of mature technology, small investment, and can improve user’s power quality effectively. Second, the application of auto voltage control on textile manufacture is analyzed. It can improve running environment of textile devices and textile quality
Authors: A. Wahab Juyana, Mohd Nazree Derman
Abstract: A porous anodic aluminium oxide (AAO) films were successfully fabricated on aluminium templates by using anodizing technique. The anodizing process was done in the mixed acid solution of phosphoric acid and acetic acid. The growth, morphology and chemical composition of AAO film were investigated. During the anodizing process, the growth of the oxide pores was strictly influenced by the anodizing parameters. The anodizing was done by varying the voltage at 70 V to 130 V and temperature from 5 °C to 25 °C. The electrolyte concentration was remaining constant. In this study, all the samples were characterized using scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques. From this study, the optimum parameters to obtain porous AAO film with the mixture of phosphoric acid and acetic acid solution can be known.
Authors: Hua Chun Zhou
Abstract: With the rapid development of science and technology, people become more expected about the intelligent experience brought by science and technology development. To operate the machine through a remote-control unit is a gift to industry from science and technology, our life is being changed by science and technology, we hope not only rely on remote-control, but also perceive our movement and then compete corresponding task according to our willing. To make the intelligent machine more acceptable to human life, and to develop an intelligent dustbin which controlled by gestures will realize interactions between human and intelligent dustbin. This article introduced the hardware circuit design of the intelligent dustbin.
Authors: Matanat Mehrabova
Abstract: Recently peaceful use of the nuclear energy and radioactive nuclides has increased the radiation pollution factor in the world and radiation safety problems have become actual ones. The development of the nuclear power engineering, protection and processing of radioactive wastes of nuclear reactors, the use of radioactive isotopes in national economy, nuclear explosion, industrial wastes and etc. may cause the radioactive pollution of the environment. In the case of such pollution the environment as well as living organisms are exposed to radioactive radiation (a-, b-, γ- etc.). Radioactive substances emit radioactive rays and as their decay time varies for natural and artificial radioactive substances the time of their environmental effect ranges from some years to million years.
Authors: Apiwat Muttamara, Pichai Janmanee
Abstract: Abstract. Wire electrical discharge machining (WEDM) is a widespread technique used in manufacturing industry for high precision machining of all types of conductive materials such as metals and its alloys of any hardness which are difficult to machine with traditional techniques. In order to get a precise workpiece with good surface quality, some extra repetitive finish cuts along the rough cutting contour are necessary. The selected parameters are servo voltage (SV) and voltage (V). The goal of the research was to obtain accurate dimension (10 + 0.005 mm and surface roughness < 0.46 microns). The experiment material is SKD-11 steel. The experiments are designed by 3k full factorial experimental design at 3 level 2 factors and 9 experiments with 2 replicates. The experiment determines the significant effective factor at confidential interval 95%. The SV factor is the significant effective factor and voltages parameter affects to the average roughness surface. Experimental results show that a surface roughness under 0.46 micron and accurate dimension value + 5 micron of 10 x 10 millimeters can be obtained.
Authors: Guang Lei Li, Xin Shi, Chun Xu Zhang, Hua Deng, Xian Zhen Zeng
Abstract: At present, distributed wind is in its infancy, so engineering practice and related technology research and development is relatively lacking. The aging problem parallel operation between wind power and power grid enterprises is the issue that the whole world should be confronted with. This paper study the influence of wind power access to power grid operation, reveal the interactive mechanism of distributed wind power and power grid, formulate the corresponding technical specification and achieve the centralized control of distributed wind power. These can be used to guide the large-scale development of distributed wind power, which makes the development of distributed wind power guided by resource type guide transition to the grid type.
Authors: Chun Hong Voon, M.N. Derman, U. Hashim, K.L. Foo
Abstract: In this study, the effect of anodizing voltage on the morphologies, pore diameter and interpore distance on the porous anodic alumina formed on aluminium manganese alloy was reported. It was found that the anodizing influenced the morphologies and regularities of porous anodic alumina formed on aluminum-manganese substrate. Well ordered porous anodic alumina was obtained when anodizing voltage were 40 V and 50 V respectively. Disordered porous anodic alumina was formed when anodizing of 30 V and 70 V were applied during the anodizing process. Both pore diameter and interpore distance of porous anodic alumina increased linearly with the anodizing voltage.
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