Research on the Key Factors of Mis-Operations and Correct Operations of the Residual Current Operated Protective Device

2014 ◽  
Vol 721 ◽  
pp. 599-602
Author(s):  
Li Min Shao ◽  
Meng Zhang ◽  
Song Huai Du
Keyword(s):  
Human Body ◽  
Low Voltage ◽  
Residual Current ◽  
Protective Device ◽  
Key Factors ◽  
Safe Operation ◽  
New Methods ◽  
Electric Power Grid ◽  
Basic Characteristics ◽  
Sinusoidal Currents

Residual Current Operated Devices (RCDs) are the protective instruments of safe operation for power system. RCDs are important components for safety against indirect contacts in low voltage installations, and employed for protection against electric shock and earth faults. In order to develop a new rule of RCD tripping directly by the human body current while shocking, it is very important to detect and identify the contact current of the human body in the summation leakage current on the low-voltage electric power grid. The new methods can solve the above problems of RCD. So, the tripping characteristics of a series of products from different RCD manufacturers were tested and analyzed under sinusoidal currents. Thus, it obtained the basic characteristics of the RCD and found out the rules and problems. The results of this study will be theoretical significant, and also can guide to developing intelligent instruments and equipment of RCD for smart grid.

Study on the Residual Current Protection Device Technology

2014 ◽  
Vol 8 (1) ◽  
pp. 404-411 ◽  
Author(s):  
Guo Rongyan ◽  
Zhang Honghui
Keyword(s):  
Distribution System ◽  
Low Voltage ◽  
Residual Current ◽  
Electrical Safety ◽  
Protective Device ◽  
Protection Device ◽  
Voltage Distribution ◽  
The People ◽  
Safety Protection ◽  
Device Technology

As an important electrical safety protection device in low voltage distribution system, residual current protection device is to protect the insulation line leakage fault; the electric shock of the people plays an important role in fault. From the protection characteristics of residual current protective device to points, those can be divided into, residual current protection device for residual pulsating direct current and residual dc, according to the residual sinusoidal alternating current.

scholarly journals BIOLOGICAL AGE AS A METHOD FOR ESTIMATING HEALTH LEVEL UNDER ENVIRONMENTAL RISKS (LITERATURE REVIEW)

2019 ◽  
Vol 98 (7) ◽  
pp. 761-765 ◽  
Author(s):  
N. I. Prokhorov ◽  
V. I. Dontsov ◽  
Vyacheslav N. Krutko ◽  
T. M. Khodykina
Keyword(s):  
Human Body ◽  
Quantitative Assessment ◽  
Modern Human ◽  
The Body ◽  
Biological Age ◽  
Whole Body ◽  
New Methods ◽  
Biomarkers Of Aging ◽  
Age Related ◽  
Definition Of

The widespread formation of unfavorable environmental, the swiftness of modern life with large information and psycho-emotional loads and extremely natural and climatic cataclysms, as well as harmful addictions and wrong way of life of modern human, lead to the development of stress and disruption of the mechanisms of adaptation of the human body and its accelerated wear. This stimulates the development of research on the creation of new methods of integrated assessment of health and quantitative assessment of the aging processes of the body systems and the whole body, as well as the possibilities of new methods of risk assessment of climatic and environmentally related pathological and age-related diseases. The aim of the work was to consider the methodology of quantitative assessment of individual health and the rate of aging of the human body on the basis of the system index of Biological age (BA); description of its essence and structure, requirements for tests - biomarkers of aging used as the index of BA, definition of possibilities and scope of application of the BA method in modern practice of Biomedicine. The use of modern methods of scientific analysis - a systematic approach to the analysis of the processes of human aging and determine its quantitative side - the value of BA, allows a reasonable approach to the choice of the number of BM, to take into account their information content and precision, and the cost of diagnostics and availability for different users, to take into account the specific objectives of the researcher. The use of the index-partial BA allows individual approaching the choice of biomarkers and create personalized panels for the definition of BA programs for the prevention of aging in personalized preventive medicine. The complexity of the content and calculation of indices of BA requires automation and the use of methods of modern computer science and computer calculations and programs. For this purpose, we have created special computer software for diagnosing aging by calculating the BA indices with the possibility of choosing BM and automatic calculation of indicators and conclusions.

scholarly journals New methods on standardization and clustering of human body for apparel engineering.

1989 ◽  
Vol 45 (5) ◽  
pp. 199-205
Author(s):  
Yoshio Shimizu ◽  
Jin Wang ◽  
Atsuo Konda ◽  
Kyoko Terada ◽  
Naoko Kumota ◽  
...  
Keyword(s):  
Human Body ◽  
New Methods

Malaria blood mass

1937 ◽  
Vol 33 (8) ◽  
pp. 948-953
Author(s):  
G. Y. Repin
Keyword(s):  
Human Body ◽  
Medical Knowledge ◽  
New Methods ◽  
Pathological Conditions

Along with the progress of medical knowledge, the discovery of new methods of research, both clinical and laboratory, the concepts of some pathological conditions of the human body are changing.

scholarly journals Testing Sensitivity of A-Type Residual Current Devices to Earth Fault Currents with Harmonics

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2044
Author(s):  
Stanislaw Czapp
Keyword(s):  
Power Systems ◽  
Electric Shock ◽  
Low Voltage ◽  
Wide Spectrum ◽  
Residual Current ◽  
Motor Speed ◽  
Earth Fault ◽  
Fault Currents ◽  
Wide Range ◽  
Sinusoidal Waveform

In many applications, modern current-using equipment utilizes power electronic converters to control the consumed power and to adjust the motor speed. Such equipment is used both in industrial and domestic installations. A characteristic feature of the converters is producing distorted earth fault currents, which contain a wide spectrum of harmonics, including high-order harmonics. Nowadays, protection against electric shock in low-voltage power systems is commonly performed with the use of residual current devices (RCDs). In the presence of harmonics, the RCDs may have a tripping current significantly different from that provided for the nominal sinusoidal waveform. Thus, in some cases, protection against electric shock may not be effective. The aim of this paper is to present the result of a wide-range laboratory test of the sensitivity of A-type RCDs in the presence of harmonics. This test has shown that the behavior of RCDs in the presence of harmonics can be varied, including the cases in which the RCD does not react to the distorted earth fault current, as well as cases in which the sensitivity of the RCD is increased. The properties of the main elements of RCDs, including the current sensor, for high-frequency current components are discussed as well.

scholarly journals Wettability and Infiltration of Liquid Silicon on Graphite Substrates

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 300 ◽  
Author(s):  
Almudena Casado ◽  
Jose Torralba ◽  
Srdjan Milenkovic
Keyword(s):  
Sessile Drop ◽  
Triple Line ◽  
Passive Layer ◽  
Sessile Drop Method ◽  
Purification Process ◽  
Key Factors ◽  
Vacuum Refining ◽  
New Methods ◽  
Solar Silicon ◽  
Infiltration Behavior

The energy crisis has stimulated a rapid growth of developments in the photovoltaic industry in recent years. To reduce the high cost and the toxicity of classical metallurgical routes, new methods, such as vacuum refining of silicon, have been developed. Moreover, at the industry level, parameters such as the porosity in crucibles and dies are not controlled, so wettability, infiltration, and reaction between silicon and graphite are the key factors in the purification process. In this work, the behavior of several refractory substrates against melted silicon was studied by the classic sessile drop method. The most important phenomena, i.e., wettability and infiltration, were compared with the properties of the substrates. According to the results, for the carbonaceous materials, the reaction of triple line silicon-graphite manages these phenomena, whereas for alumina, a passive layer is formed due to the presence of oxygen, which is subsequently eliminated by the chemical reactions, delaying the process. Regarding the contact angle and infiltration behavior, alumina showed the best results, but due to its reactivity, it contaminates Si, so that this material is not recommended for solar silicon application. However, composite 2 is compatible with the application, as it shows good results in comparison with the other materials.

A Micro Pump Driven by Conducting Polymer Soft Actuator Based on Polypyrrole

2009 ◽  
Author(s):  
Yoshitaka Naka ◽  
Masaki Fuchiwaki ◽  
Kazuhiro Tanaka
Keyword(s):  
Energy Consumption ◽  
Conducting Polymer ◽  
Low Voltage ◽  
Flow Rates ◽  
Soft Actuator ◽  
Micro Pump ◽  
Consumption Rates ◽  
Basic Characteristics ◽  
Soft Actuators ◽  
Transport Fluid

Micro pumps with various driving systems have been developed and they have been carried out with experimental and numerical approaches so far. The authors propose a micro pump with soft actuators by conducting polymers as a driving source. The purpose of the present study is to develop the micro pump driven by conducting polymer soft actuator based on polypyrrole and to clarify the basic characteristics of the micro pump. Especially, we measure the flow rates, delivery heads and energy consumption of the micro pump driven by conducting polymer soft actuators and compare these results with those of the conventional micro pumps. The micro pump driven by a conducting polymer soft actuator can transport fluids in one direction without backflow by two soft actuators with opening and closing movement. Furthermore, wider ranges of flow rates are obtained with this micro pump and greater maximum delivery heads are obtained by them Moreover, the influence of the viscosity of the transport fluid was small and the micro pump driven by the conducting polymer soft actuator can transport fluid even with the viscosity that is 400 times as great as that of water in addition. The energy consumption rates of our micro pump are dramatically lower than those of the conventional micro pumps. This is because a conducting polymer soft actuator drives with a low voltage and a micro pump with low energy consumption is realized here.

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