Improving the Critical Electric Drives Reliability at Industrial Power Plants of Metallurgical Enterprises

2002 ◽

Vol 216 (2) ◽

pp. 183-197

Author(s):

L M C Mhango ◽

R Perryman

Keyword(s):

High Speed ◽

Nuclear Power ◽

Power Plants ◽

Magnetic Bearings ◽

First Century ◽

Active Magnetic Bearings ◽

Electric Drives ◽

Gas Processing ◽

Recent Developments ◽

Gas Circulation

The combination of advances in active magnetic bearings, recent developments in power electronics technology, new design techniques of electrical machines and advances in magnetic materials is contributing to innovative forms of submerged high-speed electric drives which will be suitable for special gas processing applications well into the twenty-first century. Typical applications include submerged industrial high-pressure and high-temperature gas processes, calibration of gas meters, gas circulation in nuclear power plants, etc. This paper looks at the results of case studies of high-speed drives and discusses their benefits and advantages.

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TRANSIENT PROCESSES OF SWITCHED RELUCTANCE MOTOR IN ELECTRICAL ENGINEERING SYSTEM OF PHOTOVOLTAIC PANEL ON SHIPBOARD

VESTNIK OF ASTRAKHAN STATE TECHNICAL UNIVERSITY SERIES MARINE ENGINEERING AND TECHNOLOGIES ◽

10.24143/2073-1574-2019-3-105-112 ◽

2019 ◽

pp. 105-112

Author(s):

Aleksej Vladimirovich Melikov

Keyword(s):

Mathematical Model ◽

Electric Drive ◽

Power Plants ◽

Solar Power ◽

Tracking System ◽

Switched Reluctance Motor ◽

Switched Reluctance ◽

Electric Drives ◽

Reluctance Motor ◽

Solar Power Plants

The article describes using small off-line solar power plants transforming solar energy into electric energy on shipboard for domestic needs: heating, lighting, pumping etc. It has been stated that in solving problems of increasing the reliability and efficiency of installing solar panels, as well as reducing the consumed electric power, electric solar power systems with jet-valve electric drives seem very promising. Using gearless electric drives in solar power plants contributes to increased accuracy of precision automatic control systems. In the researches related to jet valve machines there is found a lack in the description of a method for calculating engine parameters for a solar power system depending on the real area and panel size. For studying the characteristics of the drive transients a mathematical model is analyzed and its algorithm is presented, in which the end-to-end calculation method is used. According to this method, the initial parameters of the engine are set first, then the main dimensions and parameters of the magnetic circuit are calculated, and in the end the operating characteristics of the electric drive are determined. The dependences of the motor torque on the angle of rotation, current and inductance are calculated, as well as the flux linkage of the switched reluctance motor. The drive transient simulation has been performed. An increase of the mathematical model performance was achieved by introducing an angle identifier into the tracking system. The problem of using the rotor position sensors, which is not always possible, was solved by applying methods of indirect determining the position of angle of the rotor. It has been stated that the electrotechnical system with switched reluctance motor used in the tracking system (as well as in other types of electric drive) is widely popular due to high reliability of the solar power plant, simplicity of its design and low cost, as well as accurate positioning in the process of solar panel alignment.

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Improvement of power supply quality at a modern mining and processing plant

Gornyi Zhurnal ◽

10.17580/gzh.2020.12.19 ◽

2020 ◽

pp. 82-86

Author(s):

G. P. Kornilov ◽

◽

I. R. Abdulveleev ◽

Yu. N. Kondrashova ◽

K. E. Odintsov ◽

...

Keyword(s):

Power Supply ◽

Power Plants ◽

Electromagnetic Compatibility ◽

Economic Effect ◽

Processing Plant ◽

Variable Speed ◽

Variable Speed Drives ◽

Electric Drives ◽

Basic Power ◽

Chelyabinsk Region

The article discusses power supply quality in an industry in terms of Mikheevsky GOK—one the largest mining and processing plants in the Chelyabinsk Region and in Russia. The power supply quality is understood here as the reliability, economic efficiency and electromagnetic compatibility of basic power consumers. These objectives can be successively achieved through in-house power generation by gas piston power plants, as well as thanks to banks of supercapacitors capable to maintain power factor within the present ranges. The capital expenses connected with buying mill electric drives with capacity to tens megawatts are appreciably cut down owing to an original decision to use asynchronous motors with phase-wound rotors and liquid rheostats, which were commonly used at the dawn of adjustable electric drives. That decision allowed rejecting expensive variable speed drives at admissible power quality. Design and installation of capacitors with current-limiting coils neglected harmonics of lowvoltage variable speed drives and follow-up resonances, which resulted in overcurrents and in failure of the capacitors. Finally, the plant sustained considerable losses. The way out of this situation is shown by the research and modeling as series connection of currentlimiting coils and filters set to suppress outer lowest harmonics (5, 7, 11) in the canonical series. The economic effect and payback period of the implementation of the proposed solution are governed, first, by the extended failure-free operation of capacitors due to elimination of overcurrents and reduction in energy loss in wattless power flows and, second, by zero extra expenses connected with installation of filter-equipped coils. The study was supported by the President of the Russian Federation, Grant for Young Candidates of Sciences—MK-499.2020.8.

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Use of fractals to describe microstructures of porous thick-film platinum electrodes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100121971 ◽

1992 ◽

Vol 50 (1) ◽

pp. 314-315

Author(s):

Steven D. Toteda

Keyword(s):

Fractal Dimension ◽

Power Plants ◽

Electrical Response ◽

Cubic Phase ◽

Platinum Electrodes ◽

Fine Grained ◽

Impedance Response ◽

Platinum Particles ◽

Energy Surfaces ◽

Highly Porous

Zirconia oxygen sensors, in such applications as power plants and automobiles, generally utilize platinum electrodes for the catalytic reaction of dissociating O2 at the surface. The microstructure of the platinum electrode defines the resulting electrical response. The electrode must be porous enough to allow the oxygen to reach the zirconia surface while still remaining electrically continuous. At low sintering temperatures, the platinum is highly porous and fine grained. The platinum particles sinter together as the firing temperatures are increased. As the sintering temperatures are raised even further, the surface of the platinum begins to facet with lower energy surfaces. These microstructural changes can be seen in Figures 1 and 2, but the goal of the work is to characterize the microstructure by its fractal dimension and then relate the fractal dimension to the electrical response. The sensors were fabricated from zirconia powder stabilized in the cubic phase with 8 mol% percent yttria. Each substrate was sintered for 14 hours at 1200°C. The resulting zirconia pellets, 13mm in diameter and 2mm in thickness, were roughly 97 to 98 percent of theoretical density. The Engelhard #6082 platinum paste was applied to the zirconia disks after they were mechanically polished ( diamond). The electrodes were then sintered at temperatures ranging from 600°C to 1000°C. Each sensor was tested to determine the impedance response from 1Hz to 5,000Hz. These frequencies correspond to the electrode at the test temperature of 600°C.

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The Effects of Ion Implantation on the Surface Features of Inconel 600

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118333 ◽

1985 ◽

Vol 43 ◽

pp. 288-289

Author(s):

John D. Rubio

Keyword(s):

Grain Boundary ◽

Ion Implantation ◽

Nuclear Power ◽

Power Plants ◽

Surface Region ◽

Selective Dissolution ◽

Boundary Region ◽

Near Surface ◽

Inconel 600 ◽

Steam Generator Tubing

The degradation of steam generator tubing at nuclear power plants has become an important problem for the electric utilities generating nuclear power. The material used for the tubing, Inconel 600, has been found to be succeptible to intergranular attack (IGA). IGA is the selective dissolution of material along its grain boundaries. The author believes that the sensitivity of Inconel 600 to IGA can be minimized by homogenizing the near-surface region using ion implantation. The collisions between the implanted ions and the atoms in the grain boundary region would displace the atoms and thus effectively smear the grain boundary.To determine the validity of this hypothesis, an Inconel 600 sample was implanted with 100kV N2+ ions to a dose of 1x1016 ions/cm2 and electrolytically etched in a 5% Nital solution at 5V for 20 seconds. The etched sample was then examined using a JEOL JSM25S scanning electron microscope.

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