scholarly journals Improving the efficiency of electric network equipment operational service

2019 ◽  
Vol 114 ◽  
pp. 03001
Author(s):  
Elena Rychagova ◽  
Vladimir M. Levin
Keyword(s):  
Mathematical Model ◽  
Distribution System ◽  
Optimal Solution ◽  
Electrical Equipment ◽  
Optimal Time ◽  
Time Intervals ◽  
Electric Network ◽  
Real Distribution ◽  
Network Equipment ◽  
Optimization Methodology

Maintenance and repair (M&R) of electric network equipment is one of the crucial methods for reliable power supplying. For implementing the condition based maintenance strategy is necessary to solve a number of problems, including prioritizing of preventive measures order and determining optimal time of their periodic. This paper points out two specific aspects: 1) development of an adequate reliability simulation model to optimize the operational factors of electric network equipment; 2) advantages of the proposed M&R optimization methodology in the operational process of real distribution system. Developed probabilistic mathematical model of M&R allows determining criteria for obtaining the optimal solution according to the results of numerical calculations procedures. Described mathematical model is based on the theory of controlled Markov processes. This mathematical method allows describing “ageing” systems. The main advantages of the model are the possibility of considering all random processes for described type of equipment and obtaining the analytical solutions for basic reliability and economical indexes. Based on this, the criterions and strategy for choosing an optimal time intervals of M&R procedures have been formed. Improving the efficiency of M&R of electrical equipment is considered on a real distribution network.

scholarly journals An Efficient Mathematical Model for Distribution System Reconfiguration Using AMPL

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Meisam Mahdavi ◽  
Hassan Haes Alhelou ◽  
Nikos D. Hatziargyriou ◽  
Amer Al-Hinai
Keyword(s):  
Mathematical Model ◽  
Distribution System ◽  
System Reconfiguration ◽  
Distribution System Reconfiguration

scholarly journals Optimum Distribution System Expansion Planning Incorporating DG Based on N-1 Criterion for Sustainable System

2021 ◽  
Vol 13 (12) ◽  
pp. 6708
Author(s):  
Hamza Mubarak ◽  
Nurulafiqah Nadzirah Mansor ◽  
Hazlie Mokhlis ◽  
Mahazani Mohamad ◽  
Hasmaini Mohamad ◽  
...  
Keyword(s):  
Power Systems ◽  
Distribution System ◽  
Industrial Revolution ◽  
Optimal Solution ◽  
Search Space ◽  
Planning Problem ◽  
System Expansion ◽  
Optimum Distribution ◽  
Optimal Sizing ◽  
Expansion Planning

Demand for continuous and reliable power supply has significantly increased, especially in this Industrial Revolution 4.0 era. In this regard, adequate planning of electrical power systems considering persistent load growth, increased integration of distributed generators (DGs), optimal system operation during N-1 contingencies, and compliance to the existing system constraints are paramount. However, these issues need to be parallelly addressed for optimum distribution system planning. Consequently, the planning optimization problem would become more complex due to the various technical and operational constraints as well as the enormous search space. To address these considerations, this paper proposes a strategy to obtain one optimal solution for the distribution system expansion planning by considering N-1 system contingencies for all branches and DG optimal sizing and placement as well as fluctuations in the load profiles. In this work, a hybrid firefly algorithm and particle swarm optimization (FA-PSO) was proposed to determine the optimal solution for the expansion planning problem. The validity of the proposed method was tested on IEEE 33- and 69-bus systems. The results show that incorporating DGs with optimal sizing and location minimizes the investment and power loss cost for the 33-bus system by 42.18% and 14.63%, respectively, and for the 69-system by 31.53% and 12%, respectively. In addition, comparative studies were done with a different model from the literature to verify the robustness of the proposed method.

scholarly journals Time-jerk optimal trajectory planning of hydraulic robotic excavator

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110346
Author(s):  
Yunyue Zhang ◽  
Zhiyi Sun ◽  
Qianlai Sun ◽  
Yin Wang ◽  
Xiaosong Li ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Trajectory Planning ◽  
Optimal Trajectory ◽  
High Efficiency ◽  
Optimal Solution ◽  
Optimal Time ◽  
Target Point ◽  
Robotic Excavator ◽  
The Impact ◽  
Optimal Trajectory Planning

Due to the fact that intelligent algorithms such as Particle Swarm Optimization (PSO) and Differential Evolution (DE) are susceptible to local optima and the efficiency of solving an optimal solution is low when solving the optimal trajectory, this paper uses the Sequential Quadratic Programming (SQP) algorithm for the optimal trajectory planning of a hydraulic robotic excavator. To achieve high efficiency and stationarity during the operation of the hydraulic robotic excavator, the trade-off between the time and jerk is considered. Cubic splines were used to interpolate in joint space, and the optimal time-jerk trajectory was obtained using the SQP with joint angular velocity, angular acceleration, and jerk as constraints. The optimal angle curves of each joint were obtained, and the optimal time-jerk trajectory planning of the excavator was realized. Experimental results show that the SQP method under the same weight is more efficient in solving the optimal solution and the optimal excavating trajectory is smoother, and each joint can reach the target point with smaller angular velocity, and acceleration change, which avoids the impact of each joint during operation and conserves working time. Finally, the excavator autonomous operation becomes more stable and efficient.

Voltage Sag Evaluation Method of a Real Distribution System Based on a Connection Number Model

2013 ◽  
Vol 341-342 ◽  
pp. 1363-1366
Author(s):  
Lang Bai ◽  
Le Yu
Keyword(s):  
Distribution System ◽  
Evaluation Method ◽  
Assessment Model ◽  
Voltage Sag ◽  
Voltage Sags ◽  
Connection Number ◽  
Reliability Parameters ◽  
Real Distribution ◽  
System Components ◽  
Simulation Results

The evaluation results of power system are greatly influenced by the reliability parameters and uncertainty of system components. The connection number assessment model and an approach have been presented to assess the occurrence frequency due to voltage sags. The proposed method had been applied to a real distribution system. Compared with the interval number method, the simulation results have shown that this method is simple and flexible.

Modeling the Growth of Salmonella in Cut Red Round Tomatoes as a Function of Temperature

2010 ◽  
Vol 73 (8) ◽  
pp. 1502-1505 ◽  
Author(s):  
WENJING PAN ◽  
DONALD W. SCHAFFNER
Keyword(s):  
Mathematical Model ◽  
Growth Rates ◽  
Low Temperatures ◽  
Safety Concern ◽  
Time Intervals ◽  
Salmonella Serotypes ◽  
Increasing Temperature ◽  
Incubation Temperatures ◽  
Raw Poultry ◽  
The Relationship

Tomato-associated Salmonella outbreaks have recently become a significant food safety concern. Temperature abuse of cut tomatoes may have played a role in some of these outbreaks. The purpose of this study was to develop a mathematical model to describe the growth of Salmonella on cut tomatoes at various temperatures. Four Salmonella serotypes (Typhimurium, Newport, Javiana, and Braenderup) obtained from previous tomato-linked cases of salmonellosis were used in this study. These four serotypes were cultured separately, combined into a cocktail, and inoculated onto whole red round tomatoes and allowed to dry overnight. The tomatoes were then cut into pieces and incubated at a predetermined range of temperatures (10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, and 35°C). Salmonella concentration was measured at specified time intervals to determine the growth curve for Salmonella on cut tomatoes at each temperature. The growth rates were calculated using DMFit and used to build a mathematical model to illustrate the relationship between the growth rates of Salmonella on tomatoes and incubation temperatures from 10 to 35°C. The resulting model compared favorably with a Salmonella growth model for raw poultry developed by our laboratory. The Pathogen Modeling Program underpredicted growth at low temperatures and overpredicted growth at high temperatures. ComBase predicted consistently slower growth rates than were observed in tomatoes but showed parallel increases in growth rate with increasing temperature.

Timing of Aldicarb Applications to Control Meloidogyne arenaria in Peanut1

2001 ◽  
Vol 28 (2) ◽  
pp. 73-75 ◽  
Author(s):  
J. R. Rich ◽  
D. W. Gorbet
Keyword(s):  
Arachis Hypogaea ◽  
Chemical Treatment ◽  
Optimal Time ◽  
Meloidogyne Arenaria ◽  
Root Knot Nematode ◽  
Population Densities ◽  
Time Intervals ◽  
Yield Increase ◽  
Post Harvest ◽  
Chemical Treatments

Abstract Four fieldtrialswere conductedin northwest Florida to determine the efficacyofaldicarb appliedat varyingtime intervals after planting on peanut (Arachis hypogaea) to manage the peanut root-knot nematode, Meloidogyne arenaria. Initial treatments with aldicarb (Temik 15G), fenamiphos (Nemacur 15G), and phorate (Thimet 15G) were made at planting of peanut cv. Southern Runner. The chemicals were applied as 20-cm-wide bands over the open seed furrow using a tractor-mounted Gandy applicator. Post-plant treatments were made with a Gandy applicator at time intervals from 28 to 104 dafter planting as 36-cm-wide bands over the row centers. Post-harvest M. arenaria population densities were affected little by any chemical treatment compared to the control. The efficacy of the chemical treatments was variable and averaged onlya 295-kglha yield increase for the single at-plant applications of aldicarb compared to the control. Allat-plant + post-plant aldicarb treatments increased yield over the control by an average of712 kg¡ ha. Results from these trials did not establish a single optimal time for post-plant application of aldicarb on peanut. Data from these tests, however, indicated that a post-plant aldicarb treatment can be applied latter than previously recommended in Florida.

scholarly journals Modern trends of the world market of electrical equipment

2021 ◽  
pp. 5-9
Author(s):  
Tetiana AVERIKHINA ◽  
Maryna BURIACHENKO ◽  
Valeriia VASYLIEVA
Keyword(s):  
Renewable Energy ◽  
Smart Grid ◽  
Distribution System ◽  
Distribution Systems ◽  
Renewable Energy Sources ◽  
Electrical Equipment ◽  
World Market ◽  
Global Market ◽  
The World ◽  
Transmission And Distribution

Introduction. The world market of electrical equipment is developing very fast. There are many companies in the market that sell electrical equipment, among them there are companies that occupy leading positions. Today, the world market of energy engineering is estimated at 87 billion dollars per year, based on the structural dynamics of growth, the annual volume can reach 110-115 billion dollars per year until 2025. The global market for energy equipment service in 2020 is 31.7 billion dollars, including: LTSA (long-term service) 47 %, modernization – 20 %, field service – 24 %, engineering – 9 %. The purpose of the paper is to analyze the world market of electrical equipment, determine sales, business growth. The list of leaders in electrical equipment on the world market is considered. Results. The main trends in the world today are the following areas: development of DC transmission system, cable lines for underwater laying and cable for connections of renewable energy sources to reduce energy transmission costs through the capabilities of existing transmission lines, through network voltages and innovative design solutions and installation methods. The amendment for these trends shows us the world leaders in the electrical market, such as Legrand, Schneider Electric, ABB, Siemens, DEKraft, SASSIN, EKF, etc., R&D costs are 3.5–5 % of profits (over 60 years). Thus, we can conclude that the global market for cable networks is developing rapidly. This market is expected to grow in the development of smart grid technologies, renewable energy generation and initiatives to modernize the transmission and distribution system. Conclusion. That the global cable ladder market is developing rapidly. This market is expected to grow in the development of smart grid technologies, renewable energy cultivation and government initiatives to modernize transmission and distribution systems.

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