The Influence of Main Pump with High-Voltage Variable Frequency Drives on Electric Motors Periodic Repair

2014 ◽  
Vol 698 ◽  
pp. 3-6 ◽  
Author(s):  
V.A. Shabanov ◽  
M.I. Khakimyanov ◽  
E.F. Khakimov
Keyword(s):  
Service Life ◽  
High Voltage ◽  
Residual Life ◽  
Variable Frequency ◽  
Electric Motors ◽  
Start Time ◽  
Variable Frequency Drive ◽  
Oil Companies ◽  
Cyclic Transfer ◽  
The Impact

The main objective of the work - to investigate the effect on the wear of high voltage electric motors of main pump units periodic switching on and off in cyclical pumping. Frequent starts motors in a cyclic pumping lead to accelerated wear of the mechanical parts of the motor due to the impact of dynamic loads at start-up, as well as winding insulation due to high inrush currents flow. As a result of accelerated depreciation may decrease residual life, overhaul period and service life of electric motors. The main factor affecting the service life of insulation motors are winding temperature, and as a consequence, the thermal aging of the insulation. The use of variable frequency drive can significantly reduce the cyclic transfer modes, or even eliminate them. The authors obtained analytical expressions for the evaluation of insulation deterioration at the start of the motor, which allow us to study the impact of the following factors: insulation class, the start time, break time at work, initial and nominal temperature, the temperature rise of the windings over the ambient temperature. The effect on the deterioration of the insulation cold start and hot conditions, as well as the percentage of the hottest start-ups in the total number of starts. Obtained expressions for the depreciation of isolation to determine the change timing of overhauls of high voltage electric main pump units. The developed method was approved by the example of the use of a variable frequency drive on the oil pumping stations construction section Leninsk-Nurlino trunk pipeline Nizhnevartovsk - Kurgan - Kuibyshev. The analysis showed that the installation of a variable frequency drive motors on three main pump units technological area of the number of starts to decline by 14%. The results can be used for pipeline transport of oil companies when planning the timing and costs of the current and capital repairs of high voltage electric motors main pump units.

scholarly journals Rationale for main fans service life in the conditions of changing load

2020 ◽  
pp. 102-108
Author(s):  
Kopachev Valerii ◽  
Keyword(s):  
Service Life ◽  
Residual Life ◽  
Mine Ventilation ◽  
Functional Condition ◽  
Structural Features ◽  
Physical Factors ◽  
Differential Analysis ◽  
Functional Efficiency ◽  
The Impact ◽  
Standard Service

Research aim is to study basic regularities in functional condition change of main fans included in the confi guration of main mine ventilation installations depending on the technological service conditions. The research also aims to determine the standard service life of main fans with the account of the diff erential analysis of the destructive factors, structural features, intensity and modes of operation of ventilation plants. 108 "Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal". No. 6. 2020 ISSN 0536-1028 Research methodology. Based on the analysis of main fan installations structure and differential analysis of technological factors affecting the functional efficiency of main fans, a mathematical model has been proposed which determines the standard and residual life of the main fan with the account of the changing load. Results and analysis. As a result of studying the impact of destructive factors on the main functional parts of the main fan, an equation has been proposed, which takes into account the physical properties of the material the fan elements are made of together with the quantitative effect of the external physical factors on the machine’s operation. Research results show that the resource of the main fans should be determined based on the useful life of the machine’s major component, i.e. mainshaft, with the account of the machine’s operation mode. Conclusions and scope of results. Circuit designs of mine ventilation plants predetermine the main fans service life. The service life should be established at the stage of the detail design with the account of the differential analysis of the destructive factors, structural features, intensity and operation modes of ventilation plants. The proposed methodology for main mine fans residual life determination is applied in expert organizations and Guidances on the determination of residual life of main mine fans which operate under the excess of the standard service life. The methodology may also be applied by project organizations to determine the design service life for the constructed main ventilation installations.

Differential Protection for High-Voltage Variable Frequency Motor Based on Sampled Values Algorithm

2013 ◽  
Vol 373-375 ◽  
pp. 1401-1405
Author(s):  
Shao Bo Yan ◽  
Yan Xu ◽  
Zong Jiang Mu
Keyword(s):  
High Voltage ◽  
New Method ◽  
Variable Frequency ◽  
Differential Protection ◽  
New Approach ◽  
Current Differential Protection ◽  
Calculation Results ◽  
Security Standard ◽  
The Impact ◽  
Motor Protection

With the application of inverter in high-voltage motor, the traditional current differential protection cant be used because of the variable frequency. So it adopts low sensitive current instantaneous protection as main protection, which doesnt meet the security standard of grid state. In order to improve the sensitivity and reliability of high-voltage motor protection, a new method based on current sampled values is proposed in this paper, which adapts to the variable frequency system. After a brief description about the impact of inverter on main protection of motors, it introduces the principle of sampled value current differential protection and variable RS sampled value algorithm. A matlab example is used to simulate. On the whole, the simulation and analysis of the calculation results verify the feasibility and reasonableness of the method. Therefore, it provides a new approach for the protection of high-voltage motor in variable frequency system.

Functional and operational risk as a criterion for assessing the durability of an autonomous energy system

2019 ◽  
Vol 12 (1) ◽  
pp. 56-62 ◽  
Author(s):  
A. O. Nedosekin ◽  
A. V. Smirnov ◽  
D. P. Makarenko ◽  
Z. I. Abdoulaeva
Keyword(s):  
Service Life ◽  
Structural Reliability ◽  
Residual Life ◽  
Fuzzy Random Variable ◽  
Operational Risk ◽  
Energy System ◽  
Technical System ◽  
Residual Service Life ◽  
Technological Parameters ◽  
Residual Service

The article presents new models and methods for estimating the residual service life of an autonomous energy system, using the functional operational risk criterion (FOR). The purpose of the article is to demonstrate a new method of durability evaluation using the fuzzy logic and soft computing framework. Durability in the article is understood as a complex property directly adjacent to the complex property of system resilience, as understood in the Western practice of assessing and ensuring the reliability of technical systems. Due to the lack of reliable homogeneous statistics on system equipment failures and recoveries, triangular fuzzy estimates of failure and recovery intensities are used as fuzzy functions of time based on incomplete data and expert estimates. The FOR in the model is the possibility for the system availability ratio to be below the standard level. An example of the evaluation of the FOR and the residual service life of a redundant cold supply system of a special facility is considered. The transition from the paradigm of structural reliability to the paradigm of functional reliability based on the continuous degradation of the technological parameters of an autonomous energy system is considered. In this case, the FOR can no longer be evaluated by the criterion of a sudden failure, nor is it possible to build a Markov’s chain on discrete states of the technical system. Assuming this, it is appropriate to predict the defi ning functional parameters of a technical system as fuzzy functions of a general form and to estimate the residual service life of the technical system as a fuzzy random variable. Then the FOR is estimated as the possibility for the residual life of the technical system to be below its warranty period, as determined by the supplier of the equipment.

On the effect of the periodicity of diagnostic measurements on improving the reliability of high-voltage transformers

2019 ◽  
Vol 12 (1) ◽  
pp. 18-21
Author(s):  
V. A. Tikhonov
Keyword(s):  
Service Life ◽  
High Voltage ◽  
Chromatographic Analysis ◽  
Aluminum Industry ◽  
Early Stage ◽  
Diagnostic Methods ◽  
Transformer Oil ◽  
Operating Voltage ◽  
Dissolved Gases ◽  
The Aluminum Industry

The influence of the periodicity of diagnostic measurements on the operational state of high-voltage transformers is considered. Examples of defects of switching devices of converter transformers and methods for their detection are given. The rationale for the importance of recognition of defects at an early stage of their occurrence is given. The influence of the multiplicity of overvoltages on the service life of converter transformers in the aluminum industry is investigated. Based on the analysis of the service life of converter transformers of one of the powerful aluminum plants, where 83% of converter transformers have exhausted their standard service life, it is shown that in 40% of cases it would be possible to avoid their failures, with timely detection and elimination of emerging defects. Examples of defects of OLR (on-load regulators) of converter transformers and methods for their detection are given. The importance of recognition of defects at an early stage of their occurrence is substantiated. A method for chromatographic analysis of dissolved gases in transformer oil has been developed for the qualitative determination of defects and ways to eliminate them. Examples of diagnostics of converter transformers at operating voltage and working load are given, providing the best quality operational characteristics of converter transformers. The periodicity of diagnostic measurements and the reduction of defects and failures has been substantiated. The question of diagnosing the state of the converter transformer TDNP-40000/10 at an enterprise of the aluminum industry is investigated. Currently, diagnostic methods are being developed based on chromatographic analysis of dissolved gases in transformer oil. The presented method of evaluating the operating parameters of transformers allows for the safe operation of high-voltage transformers and enables to increase the reliability of the power supply scheme of aluminum industry plants.

scholarly journals Assessment of the Visual Impact of Existing High-Voltage Lines in Urban Areas

Electricity ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 285-299
Author(s):  
Andreas Sumper ◽  
Oriol Boix-Aragones ◽  
Joan Rull-Duran ◽  
Joan Amat-Algaba ◽  
Joachim Wagner
Keyword(s):  
High Voltage ◽  
Urban Areas ◽  
Photographic Images ◽  
Sensibility Analysis ◽  
Visual Impact ◽  
The Impact

This article proposes a novel methodology to evaluate the visual impact of high-voltage lines in urban areas based on photographic images. The use of photographs allows for calculating the overall aesthetic impact while eliminating the subjective factors of the observer. To apply the proposed methodology based on photographs, the impact of the position and angle where the photograph was taken was analyzed, and a sensibility analysis was carried out. Moreover, it was applied to an application case, and a comparison with results from a previous study of a visual impact was performed. The methodology shows good performance and a better resolution of the indicator.

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