A unique mathematical optimization approach for examination of failure effects on electric power transmission grids by combined environmental and economic indicators

2017 ◽  
Vol 14 (3) ◽  
pp. 237-248
Author(s):  
Ali Azadeh ◽  
Maryam Sattarian ◽  
Azadeh Arjmand
Keyword(s):  
Power System ◽  
Electric Power ◽  
Power Flow ◽  
Power Transmission ◽  
Environmental Issues ◽  
Influential Factors ◽  
Optimization Approach ◽  
Content Type ◽  
Total Cost ◽  
The Cost

Purpose To achieve the optimum performance of electric transmission power system performance, the possibility of generators’ failure and the consequences are amongst the most important and real assumptions which should be taken into consideration. This paper aims to recognize the most influential factors on generators’ failures that can have a deep effect on the total cost and environmental issues. The integrated proposed approach is useful for investigating the generators’ failure effects on the performance of electric power transmission grids from the economic and environmental perspectives. In other words, the cost and pollution minimization policies are considered to decrease the unfavorable generators’ failure effects on electric power flow. Design/methodology/approach The data used in this study are gathered from a real case in USA in first step, the influential generator points that their failure has a significant effect on the objective function, have been recognized. Then, different failure scenarios are defined, and the optimum values in each of these scenarios through the GAMS modeling software are found. Consequently, by using a two-level factorial design approach, the critical generators across the power grid are determined. Findings The results show that by using such information, it is possible to detect the significant nodes in the power system grid and have a better maintenance plan. In addition, by means of this analysis and changing the capacity of main generators, it is possible to significantly reduce the operation costs. By comparing the indexes in case of the generator’s location, it seems that some of them are critical because of their capacity and position in the network (as their failure causes infeasibility in the model). Also, some of these deficiencies caused considerable index changes and critical consequences. Practical implications The integrated proposed approach is useful for investigating the generators’ failure effects on the performance of electric power transmission grids from the economic and environmental perspectives. In other words, the cost and pollution minimization policies are considered to decrease the unfavorable generators’ failure effects on electric power flow. Social implications This paper endeavors to recognize the most influential factors on generators’ failures that can have a deep effect on the total cost and environmental issues. Originality/value The integrated proposed approach is useful for investigating the generators’ failure effects on the performance of electric power transmission grids from the economic and environmental perspectives. In other words, the cost and pollution minimization policies are considered to decrease the unfavorable generators’ failure effects on electric power flow.

scholarly journals ON THE SIMULATION OF MODES ОF ELECTRIC POWER SYSTEMS WITH FACTS

2017 ◽  
Vol 60 (4) ◽  
pp. 341-351
Author(s):  
E. D. Halilov
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Power Flow ◽  
Power Transmission ◽  
Electric Power Systems ◽  
Active Power ◽  
Operating Conditions ◽  
Electrical Networks ◽  
Facts Devices

Power flow control is an important task of development of electric power systems. It is necessary to reduce the power loss, improve the reliability and quality of power supply and increase the power transmission. Currently, on the basis of modern power electronics effective FАСТS devices for flexible control of power system operation modes have been developed. FАСТS devices are able to simultaneously influence the voltage, the reactance, the angle between the voltages. As it is known, the calculations of the established modes of electric systems are the most frequently performed tasks at all the territorial and time levels of control and planning operations. These calculations are significant by themselves, being also an integral part of software systems of calculation of losses of power and energy in electrical networks, calculation of optimal modes and also sustainability. The need for multiple mode calculation imposes high requirements to the methods of calculation of the established modes in real time in terms of performance and reliability of the results of the solution being obtained under operating conditions of electric power systems. In traditional calculations of the established modes of electrical networks, shunt reactors, current-limiting reactors, capacitor banks, longitudinal compensation devices were accounted in the simulation as passive elements. In regard with the introduction of FACTS devices in power systems, there is an arising need to develop appropriate algorithms and implement them in the form of software for analyzing and controlling the established modes of power systems. The methodology and software for calculation of the established modes of electric networks with consideration of FACTS devices have been developed. The software makes it possible to obtain practically acceptable solutions in three outer iterations. Based on the results of numerical simulation of modes of the power system of the “Azerenergy” JSC it was determined that the application of FACTS devices can significantly increase the transmission line active power, improve voltage levels and reduce losses of active power. The dependences of flows and power losses on the control parameter of FACTS devices have been derived. 

scholarly journals MATHEMATICAL POWER FLOW MODEL IN AN ELECTRICAL SYSTEM CONTAINING A SERIAL COMPENSATOR THRISTOR CONTROLLED REACTIVE COMPONENT

2019 ◽  
Vol 2019 (3) ◽  
pp. 169-174
Author(s):  
M Misrikhanov ◽  
◽  
Sh Khamidov
Keyword(s):  
Power System ◽  
Electric Power ◽  
Power Flow ◽  
Degrees Of Freedom ◽  
Power Transmission ◽  
Electric Power System ◽  
Nonlinear Dependence ◽  
Reactive Component ◽  
Technology Application ◽  
Thyristor Control

A unified mathematical model of the power flow in a system containing a reactive component compensator consisting of capacitor banks connected in series to a thyristor control reactor is presented. The application of the FACTS (Flexible Alternative Current Transmission System - Controlled flexible DC power transmission) technology is shown to reduce the gap between the controlled and unmanaged modes of operation of the electric power system (EPS), presenting dispatching personnel with additional degrees of freedom in the management of power flows and voltages in excess and deficit areas of the electric network. The main objectives of the FACTS technology application are studied: increasing the transmission line capacity to the thermal limit; optimizing power flows in a complex heterogeneous network; increasing the static and dynamic stability of the electric power system. To assess the action of the new generation of regulators of the power system, two alternative models of power flow in the electric power system are considered. In the first model, the concept of alternating series reactance is used as a state variable. In the second model, the characteristic of the advance angle is used, given in the form of a nonlinear dependence in the problem of calculating the power flow using the Newton-Raphson method. Conclusions are made on the presented models of power flow allowing to estimate possibilities of the serial capacitor with thyristor control TCSC (Thyristor Controlled Series Capacitor), as FACTS device, on improvement of modes of functioning of electric power system.

Hybridization of training aircraft with real world flight profiles

2019 ◽  
Vol 91 (2) ◽  
pp. 353-365 ◽  
Author(s):  
Teresa Donateo ◽  
Roberto Totaro
Keyword(s):  
Power System ◽  
Electric Power ◽  
Real World ◽  
Weather Forecast ◽  
Forecast Model ◽  
Electric Power System ◽  
Power Demand ◽  
Content Type ◽  
Hybrid Electric ◽  
Modeling Strategy

Purpose The purpose of this paper is to analyze real-world flight data of a piston engine training aircraft collected from an internet-based radar service, along with wind data provided by a weather forecast model, and to use such data to design a hybrid electric power system. Design/methodology/approach The modeling strategy starts from the power demand imposed by a real-world wind-corrected flight profile, where speed and altitude are provided as functions of time, and goes through the calculation of the efficiency of the powertrain components when they meet such demand. Each component of the power system and, in particular, the engine and the propeller, is simulated as a black box with an efficiency depending on the actual working conditions. In the case of hybrid electric power system, the battery charging and discharging processes are simulated with the Shepherd model. Findings The variability of power demand and fuel consumption for a training aircraft is analyzed by applying the proposed methodology to the Piper PA-28-180 Cherokee, a very popular aircraft used for flight training, air taxi and personal use. The potentiality of hybridization is assessed by analyzing the usage of the engine over more than 90 flights. A tentative sizing of a hybrid electric power system is also proposed. It guarantees a fuel saving of about 5%. Originality/value The scientific contribution and the novelty of the investigation are related to the modeling methodology, which takes into account real-world flight conditions, and the application of hybridization to a training aircraft.

Positive behavioural support for children and adolescents with learning disabilities and behaviour that challenges: an initial exploration of service use and costs

2016 ◽  
Vol 21 (4) ◽  
pp. 169-180 ◽  
Author(s):  
Valentina Iemmi ◽  
Martin Knapp ◽  
Caroline Reid ◽  
Catherine Sholl ◽  
Monique Ferdinand ◽  
...  
Keyword(s):  
Learning Disabilities ◽  
Children And Adolescents ◽  
Service Use ◽  
Potential Cost ◽  
Content Type ◽  
Total Cost ◽  
Behavioural Support ◽  
Delphi Exercise ◽  
The Cost

Purpose Positive behavioural support has been considered as a valuable alternative to residential care for children and adolescents with learning disabilities and behaviour that challenges. While recent evidence suggests it has a positive impact on behaviour and carer ability to cope, there is little evidence of its economic costs or benefits. The paper aims to discuss this issue. Design/methodology/approach An exploratory cross-sectional study was conducted to evaluate the cost of providing positive behavioural support to ten children and adolescents with learning disabilities and behaviour that challenges living in the community in Ealing, West London. Comparison was also made with the cost estimate of possible alternative support packages for children and adolescents with learning disabilities and behaviour that challenges in the UK, as obtained through a Delphi exercise. Findings Total cost of services per child was £1,454 per week for young people supported short-term, and £1,402 supported long-term. Children and adolescents were making use of a range of social care, education and health services. Over the full sample, half of the total cost was accounted for by education services. The Delphi exercise estimated the weekly cost of residential-based care as more expensive than the cost of community-based care for children and adolescents with learning disabilities and behaviour that challenges. At the end of the ITSBS, all ten children and adolescents initially at risk of imminent residential placement were living in the community with less service-intensive and less expensive support. This suggests that avoiding residential-based care could reduce costs in the long term. Originality/value Positive behavioural support has potential to support people with learning disabilities and behaviour that challenges in the community, leading to potential cost advantages. However, this is a small study and more robust research is needed.

scholarly journals Optimal Sizing and Spatial Allocation of Storage Units in a High-Resolution Power System Model

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3365 ◽  
Author(s):  
Lukas Wienholt ◽  
Ulf Müller ◽  
Julian Bartels
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Power Transmission ◽  
Renewable Generation ◽  
Large Power ◽  
Transmission Grid ◽  
Storage Units

The paradigm shift of large power systems to renewable and decentralized generation raises the question of future transmission and flexibility requirements. In this work, the German power system is brought to focus through a power transmission grid model in a high spatial resolution considering the high voltage (110 kV) level. The fundamental questions of location, type, and size of future storage units are addressed through a linear optimal power flow using today’s power grid capacities and a generation portfolio allowing a 66% generation share of renewable energy. The results of the optimization indicate that for reaching a renewable energy generation share of 53% with this set-up, a few central storage units with a relatively low overall additional storage capacity of around 1.6 GW are required. By adding a constraint of achieving a renewable generation share of at least 66%, storage capacities increase to almost eight times the original capacity. A comparison with the German grid development plan, which provided the basis for the power generation data, showed that despite the non-consideration of transmission grid extension, moderate additional storage capacities lead to a feasible power system. However, the achievement of a comparable renewable generation share provokes a significant investment in additional storage capacities.

A Model of Continuous Optimized Power Flow with DR

2013 ◽  
Vol 805-806 ◽  
pp. 452-457
Author(s):  
Wen Bo Mao ◽  
Ke Wang ◽  
Jian Tao Liu
Keyword(s):  
Power System ◽  
Demand Response ◽  
Cost Reduction ◽  
Power Flow ◽  
Peak Load ◽  
Load Reduction ◽  
Interruptible Load ◽  
Time Price ◽  
The Cost ◽  
Reduction Cost

A model of continuous optimized power flow (COPF) is proposed, concluding demand response (DR). According to different implementation mechanisms, a series of DR models are built, such as: time of use (TOU), real time price (RTP), critical peak price (CPP), and interruptible load (IL). The influences of these kinds of DR on power system are analyzed, including peak load reduction, cost reduction, and reservation optimization. The results show that: DR can cut the cost, reduce the peak load, and promote the reservation optimization.

Effect of ISO 9001 non-conformity process on cost of poor quality in capital-intensive sectors

2015 ◽  
Vol 32 (2) ◽  
pp. 144-155 ◽  
Author(s):  
Andrea Chiarini
Keyword(s):  
Poor Quality ◽  
Iso 9001 ◽  
Content Type ◽  
Total Cost ◽  
Periodic Maintenance ◽  
Research Findings ◽  
The Cost ◽  
First Time ◽  
Capital Intensive ◽  
Cost Of Poor Quality

Purpose – The purpose of this paper is to investigate whether there are differences in terms of the effect of the ISO 9001 non-conformity process on the cost of poor quality in different sectors. In particular, to investigate the effect on six sectors of companies which manufacture their products mainly through machines and plant (i.e. capital-intensive companies). An additional aim is to understand what the reasons for these differences are and why ISO 9001 has limitations in reducing the different categories of costs of poor quality. Design/methodology/approach – The paper is based on a questionnaire administered to a sample of 42 companies divided into six different sectors: chemical, pharmaceutical, mechanical, food, ceramic and steel. Respondents were asked to give a percentage score for the contribution the ISO 9001 non-conformity process makes to the reduction in total cost of poor quality and to its categories: scrap, rework, machine stoppage, re-inspections, rejected products and recall cost. A one-way Anova test was applied to the means of the percentage scores to determine whether there are differences between the means of the total cost of poor quality and its categories. Qualitative comments and suggestions from the companies provided information that helped explain the reasons for such differences. Findings – The results of the research show that there is no difference within and between the sectors in the means of the total cost of poor quality and scrap cost, whereas there are significant differences in the means of the other costs of poor quality between the six sectors. The ISO 9001 non-conformity process has limitations in reducing the costs of poor quality and suggestions concerning the limitations of ISO 9001 in the Research and Development process emerge. Research limitations/implications – The generalizability of the research findings is limited because of the use of just six sectors of capital-intensive companies. Further research about differences in different sectors is needed. Practical implications – The implications of this research are useful for consultants and managers who want to understand what the limitations of the ISO 9001 non-conformity process are on the cost of poor quality in the six sectors. The findings clearly show how, together with ISO 9001, they should take into account other improvement processes such as periodic maintenance and revamping. Originality/value – The paper discusses in a quantitative way and for the first time the effects of the ISO 9001 non-conformity process on the cost of poor quality.

scholarly journals A Parallel Implementation of Unscheduled Flow Control in Interconnected Power Systems

2012 ◽  
Vol 2012 ◽  
pp. 1-19
Author(s):  
G. Ozdemir Dag ◽  
Mustafa Bagriyanik
Keyword(s):  
Power Systems ◽  
Power System ◽  
Parallel Computation ◽  
High Performance ◽  
Power Flow ◽  
Parallel Implementation ◽  
Computation Time ◽  
Test System ◽  
Fuzzy Decision Making ◽  
Optimization Approach

The unscheduled power flow problem needs to be minimized or controlled as soon as possible in a deregulated power system since the transmission systems are mostly operated at their power-carrying limits or very close to it. The time spent for simulations to determine the current states of all the system and control variables of the interconnected power system is important. Taking necessary action in case of any failure of equipment or any other occurrence of an undesired situation could be critical. Using supercomputing facilities and parallel computing techniques together decreases the computation time greatly. In this study, a parallel implementation of a multiobjective optimization approach based on both genetic algorithms and fuzzy decision making to manage unscheduled flows is presented. Parallel computation techniques are applied using supercomputers (high-performance computers). The proposed method is applied to the IEEE 300 bus test system. Two different cases for some parameters of GA are considered to see the power of parallel computation technique. Then the simulation results are presented.

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