LOW-FREQUENCY ELECTROMECHANICAL VIBRATION CONVERTER BASED ON LEVITATION EFFECT

2021 ◽  
pp. 52-57
Author(s):  
A. N. Shilin ◽  
M. N. Mustafa ◽  
N. S. Kuznetsova

At present, one of the urgent problems in the energy and industry is to improve the reliability of the operation of various equipment. An effective method for increasing the reliability of equipment is diagnosing the state of machines and predicting their performance. Vibration control methods are widely used to diagnose rotary rotating machines. By the nature of the vibration process of the machine, it is possible to determine the degree of wear and, accordingly, the technical condition of the machines. In measuring technology for diagnostics of low-speed equipment with rotation frequencies of a unit of Hz, for example, hydroelectric generators of hydroelectric power plants, inertial electromechanical converters are used. The latest developments of such converters use an electromagnetic suspension with parametric feedback, which allows you to control the rigidity of the oscillatory system. However, for centering the moving part in electromechanical converters, flexible guides are used, which are sources of dry friction, which complicates the simulation of measurement processes and limits the sensitivity threshold to a minimum. In addition, flexible guides limit the frequency range of the converters. Currently, the most promising direction for solving this problem is the levitation effect, which allows you to completely exclude mechanical contact and, accordingly, reduce the sensitivity threshold of the transducer. From the analysis of literary sources, it follows that there are relatively few publications in this area. The proposed article provides an analysis of existing converters, on the basis of which a converter with improved characteristics, a measuring converter, is proposed. The proposed electromechanical converter has improved metrological characteristics and therefore can control and diagnose equipment in various fields of human activity. This problem is especially relevant in the hydropower industry.

2021 ◽  
Vol 351 ◽  
pp. 01002
Author(s):  
Klaudiusz Migawa ◽  
Agnieszka Sołtysiak ◽  
Magda Czyżewska ◽  
Sylwester Borowski ◽  
Maciej Woropay

The paper presents a semi-Markow model of a preventive repair system by age, implemented in hydroelectric power plants with Kaplan turbines. In the case of the analyzed technical objects, the profit per time unit is considered as the criterion of the quality of functioning. On the basis of the adopted assumptions, for the developed mathematical model, formulas describing the criterion function were determined and the conditions for the existence of the extreme (maximum) of this function were formulated. The proposed method makes it possible to determine the optimal time for preventive repair of the considered technical objects. The theoretical considerations presented in the work are illustrated by a computational example developed on the basis of data obtained from the actual operating system of Kaplan water turbines with a rated power of 120 kW.


Author(s):  
A. Pavelko ◽  
M. Syrotyuk

The main theoretical aspects of the environmental risks as a scientific category, the definition of environmental risk in the Ukrainian legislation, as well as major environmental risks associated with the construction and operation of hydroelectric power have been described. Taking into account the largescale plans of the hydroelectric power plants building in Ukraine after the implementation of "green" tariff the determination and issue the appropriate environmental risks assessment is crucial for making the reasonable management decisions on the construction of hydroelectric power or abandon it. Key words: environmental risk, hydropower plant.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1900
Author(s):  
Vitor Augusto Machado Jorge ◽  
Pedro Daniel de Cerqueira Gava ◽  
Juan Ramon Belchior de França Silva ◽  
Thais Mancilha ◽  
Waldir Vieira ◽  
...  

Hydroelectric power plants often make use of tunnels to redirect the flow of water to the plant power house. Such tunnels are often flooded and can span considerable distances. Periodical inspections of such tunnels are highly desirable since a tunnel collapse will be catastrophic, disrupting the power plant operation. In many cases, the use of Unmanned Underwater Vehicles (UUVs) equipped with mechanical profiling sonars is a suitable and affordable way to gather data to generate 3D mapping of flooded tunnels. In this paper, we study the resolution of 3D tunnel maps generated by one or more mechanical profiling sonars working in tandem, considering synchronization and occlusion problems. The article derives the analytical equations to estimate the sampling of the underwater tunnels using mechanical profiling sonars (scanning sonars). Experiments in a simulated environment using up to four sensors simultaneously are presented. We also report experimental results obtained by a UUV inside a large power plant tunnel, together with a first map of this environment using a single sonar sensor.


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