This paper presents the approach of fuzzy numbers for reliability calculation of electrical energy indices
and compared to an analytical method. In this paper, the fuzzy numbers which are represented by
triangular fuzzy numbers are used to evaluate the load duration curve and the probabilities capacity
generators that are in services, in term of the expected energy not supplied (EENS), loss of energy
expectation (LOEE) and the energy index of the reliability (EIR). A case study based on the Malaysia
distribution network (DISCO-Net) is carried out.The proposed method shows a simple implementation and
the results seem to be a good approximation to the analytical approach.
Artificial Intelligence Technique based Reactive Power Planning Incorporating...IDES Editor
This document summarizes a research paper that proposes using artificial intelligence techniques and FACTS controllers for reactive power planning in real-time power transmission systems. The paper formulates the reactive power planning problem and incorporates flexible AC transmission system (FACTS) devices like static VAR compensators (SVC), thyristor controlled series capacitors (TCSC), and unified power flow controllers (UPFC). Evolutionary algorithms like evolutionary programming (EP) and differential evolution (DE) are applied to find the optimal locations and settings of the FACTS controllers to minimize losses and costs. Simulation results on IEEE 30-bus and 72-bus Indian test systems show that UPFC performs best in reducing losses compared to SVC and TCSC.
The effect of load modelling on phase balancing in distribution networks usin...IJECEIAES
Due to the unequal loads in phases and different customer consumption, the distribution network is unbalanced. Unbalancing in the distribution network, in addition to increasing power losses, causes unbalancing in voltages and increases operating costs. To reduce this unbalancing, various methods and algorithms have been presented. In most studies and even practical projects due to lack of information about the network loads, load models such as constant power model, constant current or constant impedance are used to model the loads. Due to the changing and nonlinear behaviours of today's loads, these models cannot show results in accordance with reality. This paper while introducing an optimal phase-balancing method, discusses the effect of load modelling on phase balancing studies. In this process the re-phasing method for balancing the network and the harmony search algorithm for optimizing the phase displacement process have been used. The simulation was carried out on an unbalanced distribution network of 25 buses. The results show well the effect of this comprehensive modelling on phase balancing studies. It also shows that in the re-phasing method for balancing the network and in the absence of a real load model, the use of which model offers the closest answer to optimal solutions.
Estimation of Weekly Reference Evapotranspiration using Linear Regression and...IDES Editor
The study investigates the applicability of linear
regression and ANN models for estimating weekly reference
evapotranspiration (ET0) at Tirupati, Nellore, Rajahmundry,
Anakapalli and Rajendranagar regions of Andhra Pradesh.
The climatic parameters influencing ET0 were identified
through multiple and partial correlation analysis. The
sunshine, temperature, wind velocity and relative humidity
mostly influenced the study area in the weekly ET0 estimation.
Linear regression models in terms of the climatic parameters
influencing the regions and, optimal neural network
architectures considering these climatic parameters as inputs
were developed. The models’ performance was evaluated with
respect to ET0 estimated by FAO-56 Penman-Monteith method.
The linear regression models showed a satisfactory
performance in the weekly ET0 estimation in the regions
selected for the present study. The ANN (4,4,1) models,
however, consistently showed a slightly improved performance
over linear regression models.
Optimal SVC allocation via symbiotic organisms search for voltage security im...TELKOMNIKA JOURNAL
It is desirable that a power system operation is in a normal operating condition. However, the increase of load demand in a power system has forced the system to operate near to its stability limit whereby an increase in load poses a threat to the power system security. In solving this issue, optimal reactive power support via SVC allocation in a power system has been proposed. In this paper, Symbiotic Organisms Search (SOS) algorithm is implemented to solve for optimal allocation of SVC in the power system. IEEE 26 Bus Reliability Test System is used as the test system. Comparative studies are also conducted concerning Particle Swarm Optimization (PSO) and Evolutionary Programming (EP) techniques based on several case studies. Based on the result, SOS has proven its superiority by producing higher quality solutions compared to PSO and EP. The results of this study can benefit the power system operators in planning for optimal power system operations.
Robust Evolutionary Approach to Mitigate Low Frequency Oscillation in a Multi...IDES Editor
This paper proposes a new optimization algorithm
known as Modified Shuffled Frog Leaping Algorithm (MSFLA)
for optimal designing of PSSs controller. The design problem
of the proposed controller is formulated as an optimization
problem and MSFLA is employed to search for optimal
controller parameters. An eigenvalue based objective function
reflecting the combination of damping factor and damping
ratio is optimized for different operating conditions. The
proposed approach is applied to optimal design of multimachine
power system stabilizers. Three different power
systems, A Single Machine Infinite Bus (SMIB), four-machine
of Kundur and ten-machine New England systems are
considered. The obtained results are evaluated and compared
with other results obtained by Genetic Algorithm (GA).
Eigenvalue analysis and nonlinear system simulations assure
the effectiveness and robustness of the proposed controller in
providing good damping characteristic to system oscillations
and enhancing the system dynamic stability under different
operating conditions and disturbances.
Convergence analysis of the triangular-based power flow method for AC distribu...IJECEIAES
This paper addresses the convergence analysis of the triangular-based power flow (PF) method in alternating current radial distribution networks. The PF formulation is made via upper-triangular matrices, which enables finding a general iterative PF formula that does not require admittance matrix calculations. The convergence analysis of this iterative formula is carried out by applying the Banach fixed-point theorem (BFPT), which allows demonstrating that under an adequate voltage profile the triangular-based PF always converges. Numerical validations are made, on the well-known 33 and 69 distribution networks test systems. Gauss-seidel, newton-raphson, and backward/forward PF methods are considered for the sake of comparison. All the simulations are carried out in MATLAB software.
Bulk power system availability assessment with multiple wind power plants IJECEIAES
The use of renewable non-conventional energy sources, as wind electric power energy and photovoltaic solar energy, has introduced uncertainties in the performance of bulk power systems. The power system availability has been employed as a useful tool for planning power systems; however, traditional methodologies model generation units as a component with two states: in service or out of service. Nevertheless, this model is not useful to model wind power plants for availability assessment of the power system. This paper used a statistical representation to model the uncertainty of power injection of wind power plants based on the central moments: mean value, variance, skewness and kurtosis. In addition, this paper proposed an availability assessment methodology based on application of this statistical model, and based on the 2m+1 point estimate method the availability assessment is performed. The methodology was tested on the IEEE-RTS assuming the connection of two wind power plants and different correlation among the behavior of these plants.
The document describes a two-stage method for optimal allocation of capacitors in a radial distribution system. In the first stage, loss sensitivity factors are used to calculate candidate locations for capacitors. In the second stage, a harmony search algorithm is used to minimize total costs, including capacitor costs and power loss costs, by determining the optimal capacitor sizes and numbers placed at the candidate locations. The method is tested on 33-bus and 69-bus test systems and results in reduced power losses and costs compared to the base case without capacitors.
Artificial Intelligence Technique based Reactive Power Planning Incorporating...IDES Editor
This document summarizes a research paper that proposes using artificial intelligence techniques and FACTS controllers for reactive power planning in real-time power transmission systems. The paper formulates the reactive power planning problem and incorporates flexible AC transmission system (FACTS) devices like static VAR compensators (SVC), thyristor controlled series capacitors (TCSC), and unified power flow controllers (UPFC). Evolutionary algorithms like evolutionary programming (EP) and differential evolution (DE) are applied to find the optimal locations and settings of the FACTS controllers to minimize losses and costs. Simulation results on IEEE 30-bus and 72-bus Indian test systems show that UPFC performs best in reducing losses compared to SVC and TCSC.
The effect of load modelling on phase balancing in distribution networks usin...IJECEIAES
Due to the unequal loads in phases and different customer consumption, the distribution network is unbalanced. Unbalancing in the distribution network, in addition to increasing power losses, causes unbalancing in voltages and increases operating costs. To reduce this unbalancing, various methods and algorithms have been presented. In most studies and even practical projects due to lack of information about the network loads, load models such as constant power model, constant current or constant impedance are used to model the loads. Due to the changing and nonlinear behaviours of today's loads, these models cannot show results in accordance with reality. This paper while introducing an optimal phase-balancing method, discusses the effect of load modelling on phase balancing studies. In this process the re-phasing method for balancing the network and the harmony search algorithm for optimizing the phase displacement process have been used. The simulation was carried out on an unbalanced distribution network of 25 buses. The results show well the effect of this comprehensive modelling on phase balancing studies. It also shows that in the re-phasing method for balancing the network and in the absence of a real load model, the use of which model offers the closest answer to optimal solutions.
Estimation of Weekly Reference Evapotranspiration using Linear Regression and...IDES Editor
The study investigates the applicability of linear
regression and ANN models for estimating weekly reference
evapotranspiration (ET0) at Tirupati, Nellore, Rajahmundry,
Anakapalli and Rajendranagar regions of Andhra Pradesh.
The climatic parameters influencing ET0 were identified
through multiple and partial correlation analysis. The
sunshine, temperature, wind velocity and relative humidity
mostly influenced the study area in the weekly ET0 estimation.
Linear regression models in terms of the climatic parameters
influencing the regions and, optimal neural network
architectures considering these climatic parameters as inputs
were developed. The models’ performance was evaluated with
respect to ET0 estimated by FAO-56 Penman-Monteith method.
The linear regression models showed a satisfactory
performance in the weekly ET0 estimation in the regions
selected for the present study. The ANN (4,4,1) models,
however, consistently showed a slightly improved performance
over linear regression models.
Optimal SVC allocation via symbiotic organisms search for voltage security im...TELKOMNIKA JOURNAL
It is desirable that a power system operation is in a normal operating condition. However, the increase of load demand in a power system has forced the system to operate near to its stability limit whereby an increase in load poses a threat to the power system security. In solving this issue, optimal reactive power support via SVC allocation in a power system has been proposed. In this paper, Symbiotic Organisms Search (SOS) algorithm is implemented to solve for optimal allocation of SVC in the power system. IEEE 26 Bus Reliability Test System is used as the test system. Comparative studies are also conducted concerning Particle Swarm Optimization (PSO) and Evolutionary Programming (EP) techniques based on several case studies. Based on the result, SOS has proven its superiority by producing higher quality solutions compared to PSO and EP. The results of this study can benefit the power system operators in planning for optimal power system operations.
Robust Evolutionary Approach to Mitigate Low Frequency Oscillation in a Multi...IDES Editor
This paper proposes a new optimization algorithm
known as Modified Shuffled Frog Leaping Algorithm (MSFLA)
for optimal designing of PSSs controller. The design problem
of the proposed controller is formulated as an optimization
problem and MSFLA is employed to search for optimal
controller parameters. An eigenvalue based objective function
reflecting the combination of damping factor and damping
ratio is optimized for different operating conditions. The
proposed approach is applied to optimal design of multimachine
power system stabilizers. Three different power
systems, A Single Machine Infinite Bus (SMIB), four-machine
of Kundur and ten-machine New England systems are
considered. The obtained results are evaluated and compared
with other results obtained by Genetic Algorithm (GA).
Eigenvalue analysis and nonlinear system simulations assure
the effectiveness and robustness of the proposed controller in
providing good damping characteristic to system oscillations
and enhancing the system dynamic stability under different
operating conditions and disturbances.
Convergence analysis of the triangular-based power flow method for AC distribu...IJECEIAES
This paper addresses the convergence analysis of the triangular-based power flow (PF) method in alternating current radial distribution networks. The PF formulation is made via upper-triangular matrices, which enables finding a general iterative PF formula that does not require admittance matrix calculations. The convergence analysis of this iterative formula is carried out by applying the Banach fixed-point theorem (BFPT), which allows demonstrating that under an adequate voltage profile the triangular-based PF always converges. Numerical validations are made, on the well-known 33 and 69 distribution networks test systems. Gauss-seidel, newton-raphson, and backward/forward PF methods are considered for the sake of comparison. All the simulations are carried out in MATLAB software.
Bulk power system availability assessment with multiple wind power plants IJECEIAES
The use of renewable non-conventional energy sources, as wind electric power energy and photovoltaic solar energy, has introduced uncertainties in the performance of bulk power systems. The power system availability has been employed as a useful tool for planning power systems; however, traditional methodologies model generation units as a component with two states: in service or out of service. Nevertheless, this model is not useful to model wind power plants for availability assessment of the power system. This paper used a statistical representation to model the uncertainty of power injection of wind power plants based on the central moments: mean value, variance, skewness and kurtosis. In addition, this paper proposed an availability assessment methodology based on application of this statistical model, and based on the 2m+1 point estimate method the availability assessment is performed. The methodology was tested on the IEEE-RTS assuming the connection of two wind power plants and different correlation among the behavior of these plants.
The document describes a two-stage method for optimal allocation of capacitors in a radial distribution system. In the first stage, loss sensitivity factors are used to calculate candidate locations for capacitors. In the second stage, a harmony search algorithm is used to minimize total costs, including capacitor costs and power loss costs, by determining the optimal capacitor sizes and numbers placed at the candidate locations. The method is tested on 33-bus and 69-bus test systems and results in reduced power losses and costs compared to the base case without capacitors.
Passivity Based Control for PV Applications by Using a Buck Power Converter
The use of power converters for everyday applications is becoming more and more important. Current technological applications simultaneously demand a high level of precision and performance, so DC-DC converters have a very important role in systems requiring energy level conversion and adaptation. As part of the work of this paper, we are interested in an analysis of modeling and control law synthesis approaches to ensure stability and a certain level of performance in the entire operating domain. The objective of our research work is therefore to propose a control law whose synthesis is based on a formalized (modeling & control) approach with a view to obtaining a control law adapted to the operating point. The principles used are based on the control and observation by the theory of passivity for the synthesis of control law of buck power converter for PV Applications.
Static VAR Compensators (SVCs) is a Flexible Alternating Current Transmission System (FACTS) device that can control the power flow in transmission lines by injecting capacitive or inductive current components at the midpoint of interconnection line or in load areas. This device is capable of minimizing the overall system losses and concurrently improves the voltage stability. A line index, namely SVSI becomes indicator for the placement of SVC and the parameters of SVCs are tuned by using the multi-objective evolutionary programming technique, effectively able to control the power. The algorithm was tested on IEEE-30 Bus Reliability Test System (RTS). Comparative studies were conducted based on the performance of SVC in terms of their location and sizing for installations in power system.
Multi objective-optimization-with-fuzzy-based-ranking-for-tcsc-supplementary-...Cemal Ardil
This document summarizes a research paper that investigates using multi-objective optimization and genetic algorithms to design a thyristor controlled series compensator (TCSC) controller to improve both rotor angle stability and voltage stability in a power system. The researchers formulate the controller design as a multi-objective optimization problem with the objectives of improving oscillatory stability and voltage profile. A genetic algorithm is used to generate a Pareto set of optimal solutions. A fuzzy-based method is then employed to select the best compromise solution from the Pareto set. Simulation results demonstrate the effectiveness of the proposed approach.
Adaptive maximum power point tracking using neural networks for a photovoltai...Mellah Hacene
Adaptive Maximum Power Point Tracking Using Neural Networks for a Photovoltaic Systems According Grid
Electrical Engineering & Electromechanics, (5), 57–66, 2021. https://doi.org/10.20998/2074-272X.2021.5.08
Heuristic remedial actions in the reliability assessment of high voltage dire...IJECEIAES
Planning of high voltage direct current (HVDC) grids requires inclusion of reliability assessment of alternatives under study. This paper proposes a methodology to evaluate the adequacy of voltage source converter/VSCHVDC networks. The methodology analyses the performance of the system using N-1 and N-2 contingencies in order to detect weaknesses in the DC network and evaluates two types of remedial actions to keep the entire system under the acceptable operating limits . The remedial actions are applied when a violation of these limits on the DC system occurs; those include topology changes in the network and adjustments of power settings of VSC converter stations. The CIGRE B4 DC grid test system is used for evaluating the reliability/adequacy performance by means of the proposed methodology in this paper. The proposed remedial actions are effective for all contingencies; then, numerical results are as expected. This work is useful for planning and operation of grids based on VSC-HVDC technology.
This document presents an implementation of space vector modulation (SVM) for a two-level three-phase inverter using a dSPACE DS1104 controller. It describes the principles of SVM, including voltage vector modeling, sector detection, and pulse generation. Hardware experiments were conducted to validate a SVM control algorithm developed in Simulink. Results showed line voltages from the real hardware matched simulation. THD comparisons confirmed SVM provides lower distortion and higher fundamental output than sinusoidal PWM. The dSPACE system allows real-time testing of control algorithms on actual hardware.
This document presents a new PQ controller for regulating the output of a DC source connected to a microgrid or electrical grid. The controller independently controls active and reactive power output. It compares measured active and reactive power to reference values and uses PI controllers and phase calculations to generate PWM signals for the inverter. Simulation results in MATLAB/Simulink show the controller effectively regulates active and reactive power injection according to reference values. The proposed PQ controller could be used to control distributed energy resources in interconnected microgrid systems.
This document proposes a sensorless estimator for speed, armature temperature, and resistance in brushed DC machines using a cascade-forward neural network (CFNN) and quasi-Newton BFGS backpropagation. A thermal model is used to estimate temperature without a thermal sensor. Simulation results show the CFNN estimates match the model outputs, estimating speed with less than 2% error. This approach provides sensorless simultaneous estimation of multiple parameters without some limitations of prior methods like the extended Kalman filter.
The document summarizes research on using a genetic algorithm to optimize the location and parameters of Flexible AC Transmission System (FACTS) devices in a power system. It first introduces FACTS devices and their ability to control power flow. It then describes using a genetic algorithm to simultaneously determine the optimal type, location, and rating of FACTS devices with the objectives of minimizing generation costs and power losses/voltage deviations. The methodology is tested on the IEEE 30-bus system with different FACTS device types. The results indicate the genetic algorithm approach can effectively determine the configuration of FACTS devices that increase system loadability.
Power transformer faults diagnosis using undestructive methods and ann for dg...Mellah Hacene
Power transformer faults diagnosis using undestructive methods (Roger and IEC) and artificial neural network for dissolved gas analysis applied on the functional transformer in the Algerian north-eastern: a comparative study
Bouchaoui Lahcene, Kamel Eddine Hemsas, Hacene Mellah, saad eddine benlahneche
Nowadays, power transformer aging and failures are viewed with great attention in power transmission industry. Dissolved gas analysis (DGA) is classified among the biggest widely used methods used within the context of asset management policy to detect the incipient faults in their earlier stage in power transformers. Up to now, several procedures have been employed for the lecture of DGA results. Among these useful means, we find Key Gases, Rogers Ratios, IEC Ratios, the historical technique less used today Doernenburg Ratios, the two types of Duval Pentagons methods, several versions of the Duval Triangles method and Logarithmic Nomograph. Problem. DGA data extracted from different units in service served to verify the ability and reliability of these methods in assessing the state of health of the power transformer. Aim. An improving the quality of diagnostics of electrical power transformer by artificial neural network tools based on two conventional methods in the case of a functional power transformer at Sétif province in East North of Algeria. Methodology. Design an inelegant tool for power transformer diagnosis using neural networks based on traditional methods IEC and Rogers, which allows to early detection faults, to increase the reliability, of the entire electrical energy system from transport to consumers and improve a continuity and quality of service. Results. The solution of the problem was carried out by using feed-forward back-propagation neural networks implemented in MATLAB-Simulink environment. Four real power transformers working under different environment and climate conditions such as: desert, humid, cold were taken into account. The practical results of the diagnosis of these power transformers by the DGA are presented. Practical value.....
The gravitational search algorithm for incorporating TCSC devices into the sy...IJECEIAES
This paper proposes a gravitational search algorithm (GSA) to allocate the thyristor-controlled series compensator (TCSC) incorporation with the issue of reactive power management. The aim of using TCSC units in this study is to minimize active and reactive power losses. Reserve beyond the thermal border, enhance the voltage profile and increase transmission-lines flow while continuing the whole generation cost of the system a little increase compared with its single goal base case. The optimal power flow (OPF) described is a consideration for finding the best size and location of the TCSCs devices seeing techno-economic subjects for minimizing fuel cost of generation units and the costs of installing TCSCs devices. The GSA algorithm's high ability in solving the proposed multi-objective problem is tested on two 9 and 30 bus test systems. For each test system, four case studies are considered to represent both normal and emergency operating conditions. The proposed GSA method's simulation results show that GSA offers a practical and robust highquality solution for the problem and improves system performance.
Deep segmentation of the liver and the hepatic tumors from abdomen tomography...IJECEIAES
A pipelined framework is proposed for accurate, automated, simultaneous segmentation of the liver as well as the hepatic tumors from computed tomography (CT) images. The introduced framework composed of three pipelined levels. First, two different transfers deep convolutional neural networks (CNN) are applied to get high-level compact features of CT images. Second, a pixel-wise classifier is used to obtain two outputclassified maps for each CNN model. Finally, a fusion neural network (FNN) is used to integrate the two maps. Experimentations performed on the MICCAI’2017 database of the liver tumor segmentation (LITS) challenge, result in a dice similarity coefficient (DSC) of 93.5% for the segmentation of the liver and of 74.40% for the segmentation of the lesion, using a 5-fold cross-validation scheme. Comparative results with the state-of-the-art techniques on the same data show the competing performance of the proposed framework for simultaneous liver and tumor segmentation.
Oscillatory Stability Prediction Using PSO Based Synchronizing and Damping To...journalBEEI
This paper presents the assessment of stability domains for the angle stability condition of the power system using Particle Swarm Optimization (PSO) technique. An efficient optimization method using PSO for synchronizing torque coefficients Ksand damping torque coefficients Kd to identify the angle stability condition on multi-machine system. In order to accelerate the determination of angle stability, PSO is proposed to be implemented in this study. The application of the proposed algorithm has been justified as the most accurate with lower computation time as compared to other optimization techniques such as Evolutionary Programming (EP) and Artificial Immune System (AIS). Validation with respect to eigenvalues determination, Least Square (LS) method and minimum damping ratio ξmin confirmed that the proposed technique is feasible to solve the angle stability problems.
Coordinated planning in improving power quality considering the use of nonlin...IJECEIAES
Power quality has an important role in the distribution of electrical energy. The use of non-linear load can generate harmonic spread which can reduce the power quality in the radial distribution system. This research is in form of coordinated planning by combining distributed generation placement, capacitor placement and network reconfiguration to simultaneously minimize active power losses, total harmonic distortion (THD), and voltage deviation as an objective function using the particle swarm optimization method. This optimization technique will be tested on two types of networks in the form 33-bus and 69-bus IEEE Standard Test System to show effectiveness of the proposed method. The use of MATLAB programming shows the result of simulation of increasing power quality achieved for all scenario of proposed method.
Impact analysis of actuator torque degradation on the IRB 120 robot performan...IJECEIAES
Actuators in a robot system may become faulty during their life cycle. Locked joints, free-moving joints, and the loss of actuator torque are common faulty types of robot joints where the actuators fail. Locked and free-moving joint issues are addressed by many published articles, whereas the actuator torque loss still opens attractive investigation challenges. The objectives of this study are to classify the loss of robot actuator torque, named actuator torque degradation, into three different cases: Boundary degradation of torque, boundary degradation of torque rate, and proportional degradation of torque, and to analyze their impact on the performance of a typical 6-DOF robot (i.e., the IRB 120 robot). Typically, controllers of robots are not pre-designed specifically for anticipating these faults. To isolate and focus on the impact of only actuator torque degradation faults, all robot parameters are assumed to be known precisely, and a popular closed-loop controller is used to investigate the robot’s responses under these faults. By exploiting MATLAB-the reliable simulation environment, a simscape-based quasi-physical model of the robot is built and utilized instead of an actual expensive prototype. The simulation results indicate that the robot responses cannot follow the desired path properly in most fault cases.
Frequency regulation service of multiple-areas vehicle to grid application in...IJECEIAES
Regarding a potential of electric vehicles, it has been widely discussed that the electric vehicle can be participated in electricity ancillary services. Among the ancillary service products, the system frequency regulation is often considered. However, the participation in this service has to be conformed to the hierarchical frequency control architecture. Therefore, the vehicle to grid (V2G) application in this article is proposed in the term of multiple-areas of operation. The multiple-areas in this article are concerned as parking areas, which the parking areas can be implied as a V2G operator. From that, V2G operator can obtain the control signal from hierarchical control architecture for power sharing purpose. A power sharing concept between areas is fulfilled by a proposed adaptive droop factor based on battery state of charge and available capacity of parking area. A nonlinear multiplier factor is used for the droop adaptation. An available capacity is also applied as a limitation for the V2G operation. The available capacity is analyzed through a stochastic character. As the V2G application has to be cooperated with the hierarchical control functions, i.e. primary control and secondary control, then the effect of V2G on hierarchical control functions is investigated and discussed.
The use of Markov Chain method to determine spare transformer number and loca...IJECEIAES
The purpose of this study is to develop a method to determine spare transformer number and location. Using Markov Chain method, state transition model and steady state probability was used on each 500-kV substation in order to analyze the effect of spare number and location variation with the reliability changes. To give an actual result of the case study, calculation of spare transformer number and location on 500/150 kV transformers in Java Bali System was analyzed. The steady state probability results will vary depending on the number of spare transformer, these results can then be used to assess the spare transformer needed. The variation of spare transformer location can be used to analyze the best possible location of the spare in order to satisfy the reliability required. The methodology presented shows an integrated calculation for determining the spare transformer number and location.
Emc model for modern power electronic systems for harmonics, losses & emi...eSAT Journals
Abstract
Electromagnetic compatibility of power electronic systems becomes an engineering discipline and it should be considered at the
beginning stage of a design. Thus, a power electronics design becomes more complex and challenging and it requires a good
communication between EMI and Power electronics experts. Three major issues in designing a power electronic system are Losses,
EMI and Harmonics. These issues affect system cost, size, efficiency and quality and it is a tradeoff between these factors when we
design a power converter, filter. In this paper the EMC model is discussed which should be considered while designing the power
electronics systems. The design considerations in this paper help us to remove losses, harmonics & EMI elimination and power
quality improvement of Power systems.
Index Terms: Converter, EMI, EMC, Filter, Harmonics
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Power system transient stability margin estimation using artificial neural ne...elelijjournal
This paper presents a methodology for estimating the normalized transient stability margin by using the multilayered perceptron (MLP) neural network. The complex relationship between the input variables and output variables is established by using the neural networks. The nonlinear mapping relation between the normalized transient stability margin and the operating conditions of the power system is established by using the MLP neural network. To obtain the training set of the neural network the potential energy boundary surface (PEBS) method along with time domain simulation method is used. The proposed method is applied on IEEE 9 bus system and the results shows that the proposed method provides fast and accurate tool to assess online transient stability.
MUTUAL EFFECT BETWEEN LFC AND AVR LOOPS IN POWER PLANTelelijjournal
This document discusses the interaction between the Load Frequency Control (LFC) loop and the Automatic Voltage Regulator (AVR) loop in a power plant. It presents a model that combines the LFC and AVR loops to regulate both frequency and voltage. The model is tested on a single-area power system in simulation. Results show the dynamic and steady-state responses of the combined LFC-AVR system with PID controllers minimize frequency overshoot and transient oscillations while maintaining zero steady-state error.
(Door Yuri van Helten | Cofely)
Het gebruik van talentpools binnen recruitment kent wisselende successen. Toch heeft het gebruik van talentpools grote voordelen. Tijdens deze presentatie laat Yuri van Helten zien hoe hij op succesvolle wijze talentpools introduceerde binnen Cofely. Zijn geheim; een CRM strategie voor talentpools.Yuri zal ingaan op vragen als hoe selecteer je kandidaten voor talentpools?
Deze presentatie is te downloaden op de site van Recruiting Academy, via: http://www.recruitingacademy.nl/influx-vakevent-voor-arbeidsmarktprofessionals/
Passivity Based Control for PV Applications by Using a Buck Power Converter
The use of power converters for everyday applications is becoming more and more important. Current technological applications simultaneously demand a high level of precision and performance, so DC-DC converters have a very important role in systems requiring energy level conversion and adaptation. As part of the work of this paper, we are interested in an analysis of modeling and control law synthesis approaches to ensure stability and a certain level of performance in the entire operating domain. The objective of our research work is therefore to propose a control law whose synthesis is based on a formalized (modeling & control) approach with a view to obtaining a control law adapted to the operating point. The principles used are based on the control and observation by the theory of passivity for the synthesis of control law of buck power converter for PV Applications.
Static VAR Compensators (SVCs) is a Flexible Alternating Current Transmission System (FACTS) device that can control the power flow in transmission lines by injecting capacitive or inductive current components at the midpoint of interconnection line or in load areas. This device is capable of minimizing the overall system losses and concurrently improves the voltage stability. A line index, namely SVSI becomes indicator for the placement of SVC and the parameters of SVCs are tuned by using the multi-objective evolutionary programming technique, effectively able to control the power. The algorithm was tested on IEEE-30 Bus Reliability Test System (RTS). Comparative studies were conducted based on the performance of SVC in terms of their location and sizing for installations in power system.
Multi objective-optimization-with-fuzzy-based-ranking-for-tcsc-supplementary-...Cemal Ardil
This document summarizes a research paper that investigates using multi-objective optimization and genetic algorithms to design a thyristor controlled series compensator (TCSC) controller to improve both rotor angle stability and voltage stability in a power system. The researchers formulate the controller design as a multi-objective optimization problem with the objectives of improving oscillatory stability and voltage profile. A genetic algorithm is used to generate a Pareto set of optimal solutions. A fuzzy-based method is then employed to select the best compromise solution from the Pareto set. Simulation results demonstrate the effectiveness of the proposed approach.
Adaptive maximum power point tracking using neural networks for a photovoltai...Mellah Hacene
Adaptive Maximum Power Point Tracking Using Neural Networks for a Photovoltaic Systems According Grid
Electrical Engineering & Electromechanics, (5), 57–66, 2021. https://doi.org/10.20998/2074-272X.2021.5.08
Heuristic remedial actions in the reliability assessment of high voltage dire...IJECEIAES
Planning of high voltage direct current (HVDC) grids requires inclusion of reliability assessment of alternatives under study. This paper proposes a methodology to evaluate the adequacy of voltage source converter/VSCHVDC networks. The methodology analyses the performance of the system using N-1 and N-2 contingencies in order to detect weaknesses in the DC network and evaluates two types of remedial actions to keep the entire system under the acceptable operating limits . The remedial actions are applied when a violation of these limits on the DC system occurs; those include topology changes in the network and adjustments of power settings of VSC converter stations. The CIGRE B4 DC grid test system is used for evaluating the reliability/adequacy performance by means of the proposed methodology in this paper. The proposed remedial actions are effective for all contingencies; then, numerical results are as expected. This work is useful for planning and operation of grids based on VSC-HVDC technology.
This document presents an implementation of space vector modulation (SVM) for a two-level three-phase inverter using a dSPACE DS1104 controller. It describes the principles of SVM, including voltage vector modeling, sector detection, and pulse generation. Hardware experiments were conducted to validate a SVM control algorithm developed in Simulink. Results showed line voltages from the real hardware matched simulation. THD comparisons confirmed SVM provides lower distortion and higher fundamental output than sinusoidal PWM. The dSPACE system allows real-time testing of control algorithms on actual hardware.
This document presents a new PQ controller for regulating the output of a DC source connected to a microgrid or electrical grid. The controller independently controls active and reactive power output. It compares measured active and reactive power to reference values and uses PI controllers and phase calculations to generate PWM signals for the inverter. Simulation results in MATLAB/Simulink show the controller effectively regulates active and reactive power injection according to reference values. The proposed PQ controller could be used to control distributed energy resources in interconnected microgrid systems.
This document proposes a sensorless estimator for speed, armature temperature, and resistance in brushed DC machines using a cascade-forward neural network (CFNN) and quasi-Newton BFGS backpropagation. A thermal model is used to estimate temperature without a thermal sensor. Simulation results show the CFNN estimates match the model outputs, estimating speed with less than 2% error. This approach provides sensorless simultaneous estimation of multiple parameters without some limitations of prior methods like the extended Kalman filter.
The document summarizes research on using a genetic algorithm to optimize the location and parameters of Flexible AC Transmission System (FACTS) devices in a power system. It first introduces FACTS devices and their ability to control power flow. It then describes using a genetic algorithm to simultaneously determine the optimal type, location, and rating of FACTS devices with the objectives of minimizing generation costs and power losses/voltage deviations. The methodology is tested on the IEEE 30-bus system with different FACTS device types. The results indicate the genetic algorithm approach can effectively determine the configuration of FACTS devices that increase system loadability.
Power transformer faults diagnosis using undestructive methods and ann for dg...Mellah Hacene
Power transformer faults diagnosis using undestructive methods (Roger and IEC) and artificial neural network for dissolved gas analysis applied on the functional transformer in the Algerian north-eastern: a comparative study
Bouchaoui Lahcene, Kamel Eddine Hemsas, Hacene Mellah, saad eddine benlahneche
Nowadays, power transformer aging and failures are viewed with great attention in power transmission industry. Dissolved gas analysis (DGA) is classified among the biggest widely used methods used within the context of asset management policy to detect the incipient faults in their earlier stage in power transformers. Up to now, several procedures have been employed for the lecture of DGA results. Among these useful means, we find Key Gases, Rogers Ratios, IEC Ratios, the historical technique less used today Doernenburg Ratios, the two types of Duval Pentagons methods, several versions of the Duval Triangles method and Logarithmic Nomograph. Problem. DGA data extracted from different units in service served to verify the ability and reliability of these methods in assessing the state of health of the power transformer. Aim. An improving the quality of diagnostics of electrical power transformer by artificial neural network tools based on two conventional methods in the case of a functional power transformer at Sétif province in East North of Algeria. Methodology. Design an inelegant tool for power transformer diagnosis using neural networks based on traditional methods IEC and Rogers, which allows to early detection faults, to increase the reliability, of the entire electrical energy system from transport to consumers and improve a continuity and quality of service. Results. The solution of the problem was carried out by using feed-forward back-propagation neural networks implemented in MATLAB-Simulink environment. Four real power transformers working under different environment and climate conditions such as: desert, humid, cold were taken into account. The practical results of the diagnosis of these power transformers by the DGA are presented. Practical value.....
The gravitational search algorithm for incorporating TCSC devices into the sy...IJECEIAES
This paper proposes a gravitational search algorithm (GSA) to allocate the thyristor-controlled series compensator (TCSC) incorporation with the issue of reactive power management. The aim of using TCSC units in this study is to minimize active and reactive power losses. Reserve beyond the thermal border, enhance the voltage profile and increase transmission-lines flow while continuing the whole generation cost of the system a little increase compared with its single goal base case. The optimal power flow (OPF) described is a consideration for finding the best size and location of the TCSCs devices seeing techno-economic subjects for minimizing fuel cost of generation units and the costs of installing TCSCs devices. The GSA algorithm's high ability in solving the proposed multi-objective problem is tested on two 9 and 30 bus test systems. For each test system, four case studies are considered to represent both normal and emergency operating conditions. The proposed GSA method's simulation results show that GSA offers a practical and robust highquality solution for the problem and improves system performance.
Deep segmentation of the liver and the hepatic tumors from abdomen tomography...IJECEIAES
A pipelined framework is proposed for accurate, automated, simultaneous segmentation of the liver as well as the hepatic tumors from computed tomography (CT) images. The introduced framework composed of three pipelined levels. First, two different transfers deep convolutional neural networks (CNN) are applied to get high-level compact features of CT images. Second, a pixel-wise classifier is used to obtain two outputclassified maps for each CNN model. Finally, a fusion neural network (FNN) is used to integrate the two maps. Experimentations performed on the MICCAI’2017 database of the liver tumor segmentation (LITS) challenge, result in a dice similarity coefficient (DSC) of 93.5% for the segmentation of the liver and of 74.40% for the segmentation of the lesion, using a 5-fold cross-validation scheme. Comparative results with the state-of-the-art techniques on the same data show the competing performance of the proposed framework for simultaneous liver and tumor segmentation.
Oscillatory Stability Prediction Using PSO Based Synchronizing and Damping To...journalBEEI
This paper presents the assessment of stability domains for the angle stability condition of the power system using Particle Swarm Optimization (PSO) technique. An efficient optimization method using PSO for synchronizing torque coefficients Ksand damping torque coefficients Kd to identify the angle stability condition on multi-machine system. In order to accelerate the determination of angle stability, PSO is proposed to be implemented in this study. The application of the proposed algorithm has been justified as the most accurate with lower computation time as compared to other optimization techniques such as Evolutionary Programming (EP) and Artificial Immune System (AIS). Validation with respect to eigenvalues determination, Least Square (LS) method and minimum damping ratio ξmin confirmed that the proposed technique is feasible to solve the angle stability problems.
Coordinated planning in improving power quality considering the use of nonlin...IJECEIAES
Power quality has an important role in the distribution of electrical energy. The use of non-linear load can generate harmonic spread which can reduce the power quality in the radial distribution system. This research is in form of coordinated planning by combining distributed generation placement, capacitor placement and network reconfiguration to simultaneously minimize active power losses, total harmonic distortion (THD), and voltage deviation as an objective function using the particle swarm optimization method. This optimization technique will be tested on two types of networks in the form 33-bus and 69-bus IEEE Standard Test System to show effectiveness of the proposed method. The use of MATLAB programming shows the result of simulation of increasing power quality achieved for all scenario of proposed method.
Impact analysis of actuator torque degradation on the IRB 120 robot performan...IJECEIAES
Actuators in a robot system may become faulty during their life cycle. Locked joints, free-moving joints, and the loss of actuator torque are common faulty types of robot joints where the actuators fail. Locked and free-moving joint issues are addressed by many published articles, whereas the actuator torque loss still opens attractive investigation challenges. The objectives of this study are to classify the loss of robot actuator torque, named actuator torque degradation, into three different cases: Boundary degradation of torque, boundary degradation of torque rate, and proportional degradation of torque, and to analyze their impact on the performance of a typical 6-DOF robot (i.e., the IRB 120 robot). Typically, controllers of robots are not pre-designed specifically for anticipating these faults. To isolate and focus on the impact of only actuator torque degradation faults, all robot parameters are assumed to be known precisely, and a popular closed-loop controller is used to investigate the robot’s responses under these faults. By exploiting MATLAB-the reliable simulation environment, a simscape-based quasi-physical model of the robot is built and utilized instead of an actual expensive prototype. The simulation results indicate that the robot responses cannot follow the desired path properly in most fault cases.
Frequency regulation service of multiple-areas vehicle to grid application in...IJECEIAES
Regarding a potential of electric vehicles, it has been widely discussed that the electric vehicle can be participated in electricity ancillary services. Among the ancillary service products, the system frequency regulation is often considered. However, the participation in this service has to be conformed to the hierarchical frequency control architecture. Therefore, the vehicle to grid (V2G) application in this article is proposed in the term of multiple-areas of operation. The multiple-areas in this article are concerned as parking areas, which the parking areas can be implied as a V2G operator. From that, V2G operator can obtain the control signal from hierarchical control architecture for power sharing purpose. A power sharing concept between areas is fulfilled by a proposed adaptive droop factor based on battery state of charge and available capacity of parking area. A nonlinear multiplier factor is used for the droop adaptation. An available capacity is also applied as a limitation for the V2G operation. The available capacity is analyzed through a stochastic character. As the V2G application has to be cooperated with the hierarchical control functions, i.e. primary control and secondary control, then the effect of V2G on hierarchical control functions is investigated and discussed.
The use of Markov Chain method to determine spare transformer number and loca...IJECEIAES
The purpose of this study is to develop a method to determine spare transformer number and location. Using Markov Chain method, state transition model and steady state probability was used on each 500-kV substation in order to analyze the effect of spare number and location variation with the reliability changes. To give an actual result of the case study, calculation of spare transformer number and location on 500/150 kV transformers in Java Bali System was analyzed. The steady state probability results will vary depending on the number of spare transformer, these results can then be used to assess the spare transformer needed. The variation of spare transformer location can be used to analyze the best possible location of the spare in order to satisfy the reliability required. The methodology presented shows an integrated calculation for determining the spare transformer number and location.
Emc model for modern power electronic systems for harmonics, losses & emi...eSAT Journals
Abstract
Electromagnetic compatibility of power electronic systems becomes an engineering discipline and it should be considered at the
beginning stage of a design. Thus, a power electronics design becomes more complex and challenging and it requires a good
communication between EMI and Power electronics experts. Three major issues in designing a power electronic system are Losses,
EMI and Harmonics. These issues affect system cost, size, efficiency and quality and it is a tradeoff between these factors when we
design a power converter, filter. In this paper the EMC model is discussed which should be considered while designing the power
electronics systems. The design considerations in this paper help us to remove losses, harmonics & EMI elimination and power
quality improvement of Power systems.
Index Terms: Converter, EMI, EMC, Filter, Harmonics
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Power system transient stability margin estimation using artificial neural ne...elelijjournal
This paper presents a methodology for estimating the normalized transient stability margin by using the multilayered perceptron (MLP) neural network. The complex relationship between the input variables and output variables is established by using the neural networks. The nonlinear mapping relation between the normalized transient stability margin and the operating conditions of the power system is established by using the MLP neural network. To obtain the training set of the neural network the potential energy boundary surface (PEBS) method along with time domain simulation method is used. The proposed method is applied on IEEE 9 bus system and the results shows that the proposed method provides fast and accurate tool to assess online transient stability.
MUTUAL EFFECT BETWEEN LFC AND AVR LOOPS IN POWER PLANTelelijjournal
This document discusses the interaction between the Load Frequency Control (LFC) loop and the Automatic Voltage Regulator (AVR) loop in a power plant. It presents a model that combines the LFC and AVR loops to regulate both frequency and voltage. The model is tested on a single-area power system in simulation. Results show the dynamic and steady-state responses of the combined LFC-AVR system with PID controllers minimize frequency overshoot and transient oscillations while maintaining zero steady-state error.
(Door Yuri van Helten | Cofely)
Het gebruik van talentpools binnen recruitment kent wisselende successen. Toch heeft het gebruik van talentpools grote voordelen. Tijdens deze presentatie laat Yuri van Helten zien hoe hij op succesvolle wijze talentpools introduceerde binnen Cofely. Zijn geheim; een CRM strategie voor talentpools.Yuri zal ingaan op vragen als hoe selecteer je kandidaten voor talentpools?
Deze presentatie is te downloaden op de site van Recruiting Academy, via: http://www.recruitingacademy.nl/influx-vakevent-voor-arbeidsmarktprofessionals/
techInvestigations with mode division multiplexed transmissionelelijjournal
This article presents proposed topology for mode division multiplexed link with SPDML and VCSEL, modulate electrical signal of 820nm wavelength. Transmission performance has been investigated for numerous modes, bit rates (2.5 to 10Gbps), transmission lengths of MMF (1 to 100km) and attenuation factor in conjunction with parabolic operational mode. Results illustrated successful performance up to nine modes in mode-division multiplexed transmission. Performance is improved at low data rates, illustrated higher OSNR with lower BER,-5dB attenuation factor. Though, at higher bit rate and longer
transmission length received OSNR is unsteady. It further inferred that transmission with large number of multiplexed modes result in degraded performance, augmented with minimization of mode coupling losses.Mode division multiplexed multimode optical communication can be a viable option for supplementary capacity augment in the preexisting and future fiber optic communication links.
techInvestigation of closed loop current control strategies for bridgeless in...elelijjournal
This document discusses current control strategies for a Bridgeless Interleaved SEPIC power factor correction converter. It analyzes peak current control, average current control, and non-linear carrier control techniques through MATLAB simulation. The non-linear carrier control using switch current sensing achieved the lowest total harmonic distortion of 3.42% and highest power factor of 0.9955, indicating it is the most effective method for improving power quality and regulating a sinusoidal input current. In general, closed loop current control strategies enhanced the power factor and quality compared to open loop operation.
Comparative study of methods for optimal reactive power dispatchelelijjournal
Reactive power dispatch plays a main role in order to provide good facility secure and economic operation
in the power system. In a power system optimal reactive power dispatch is supported to improve the voltage
profile, to reduce losses, to improve voltage stability, to reduce cost etc. This paper presents a brief literature survey of reactive power dispatch and also discusses a comparative study of conventional and evolutionary computation techniques applied for reactive power dispatch. The paper is useful for researchers for further research and study so that it can apply in the various areas of power system
Design and Performance Study of MMDWDM Systemselelijjournal
The rising need for bandwidth created innumerable efforts from academic and industry group towards development of most efficient optical communication networks. In order to compete it numerous investigators have designed their own novel schemes. In this view the paper presents multiple modulation dense wavelength division multiplexed transmission designed links each with a total capacity of 640Gbps and with channel to channel to spacing of 100Ghz, employing multiple modulation schemes such as non return to zero rectangular, non return to zero raised cosine, return to zero rectangular, non return to zero raised cosine, return to zero soliton, return to zero Super Gaussian. The optical transmission performance characteristics like bit error rate, Q parameter at the output have been investigated by simulating different systems for a fixed transmission length of 260kilometers. Results show that transmission performance of DWDM system with non return to zero raised cosine scheme has been better with quality factor ranging from 16 to 23dB and bit error rate ranging from 10-11 to 10-40 for detected channels at selected transmission reach (260KM) and other schemes with good performance were RZ Super Guassian DWDM and RZ Soliton DWDM systems for the same transmission reach. The transmission parameter jitter have been also investigated for each system which depict that jitter effect is more severe for return to zero systems as compared to non return to zero DWDM systems. From the performance analysis for different optical links involving different modulation schemes it can be articulated that novel modulation scheme generally improves the transmission performance and must for modern optical communication systems operating at high bit rate and longer reach.
OPTIMAL LOCATION OF SVC FOR DYNAMIC STABILITY ENHANCEMENT BASED ON EIGENVALUE...elelijjournal
Power system stability enhancement via optimal location of SVC is thoroughly investigated in this paper.The performance analysis of SVC has been carried out for IEEE 14 bus system for enhancement of small signal stability and transient stability using Power system analysis tool box (PSAT) software. The effectiveness is demonstrated through the eigen-value analysis and nonlinear time-domain simulation.The results of these studies show that the proposed approach has an excellent capability to enhance the dynamic and transient stability of the power system
(Door Mitchell van Koert | Achmea)
Na de succesvolle lancering van de corporate Arbeidsmarktcampagne ligt voor Achmea de komende jaren de focus voornamelijk op het bereiken van strategische doelgroepen. Ondanks dat Achmea de komende jaren gaat krimpen in het aantal werknemers blijft er ook de komende jaren druk staan op bepaalde cruciale doelgroepen.Tijdens deze presentatie geeft Mitchell van Koert inzicht in het gehanteerde doelgroepmarketingbeleid.
Deze presentatie is te downloaden op de site van Recruiting Academy, via: http://www.recruitingacademy.nl/influx-vakevent-voor-arbeidsmarktprofessionals/
(Door Patrick Boonstra)
Bij social recruitment denken we tegenwoordig vooral aan Linkedin, Twitter of Facebook. Zo zitten we uiteindelijk toch weer allemaal in diezelfde vijver te vissen. Door slimme inzichten uit de Big Data van het héle online speelveld (dus ook niche blogs, of nerden-forums) te halen kun je gerichter die diamantjes uit de arbeidsmarkt vissen.
Deze presentatie is te downloaden op de site van Recruiting Academy, via: http://www.recruitingacademy.nl/influx-vakevent-voor-arbeidsmarktprofessionals/
FAST VOLTAGE STABILTY INDEX BASED OPTIMAL REACTIVE POWER PLANNING USING DIFFE...elelijjournal
This Article presents an application of Fast Voltage Stability Index (FVSI) to Optimal Reactive Power
Planning (RPP) using Differential Evolution(DE). FVSI is used to identify the weak buses for the Reactive
Power Planning problem which involves process of experimental by voltage stability analysis based on the
load variation. The peak at Fast Voltage Stabilty Index secure to 1 indicates the greatest feasible connected
load and the bus with least connected load is identified as the weakest bus at the point of bifurcation. This technique is tested on the IEEE 30-bus system. The outcome confirm significant decrease in system losses and enhancementt of voltage stability with the use of Fast Voltage Stability Index based optimal Reactive Power Planning using Differential Evolution and compared with Evalutionary Programming
Comparison of upqc and dvr in wind turbine fed fsig under asymmetric faultselelijjournal
This paper presents the mitigation of faults in wind turbine connected fixed speed induction generator using unified power quality conditioner and static compensator. The UPQC consists of shunt and series converters connected back-to-back through a dc-to-dc step up converter. The presence of the dc-to-dc step converter permits the UPQC to compensate faults for long duration. The series converter is connected to the supply side whereas the shunt converter is connected to the load side. The control system of the proposed UPQC is based on Id-Iq theory. The DVR consists of shunt and series converters connected back-to-back through a dc-to-dc step up converter. The presence of the dc-to-dc step converter permits the DVR to compensate faults for long duration. The series converter is connected to the supply side whereas the shunt converter is connected to the load side. The control system of the proposed DVR is based on
hysteresis voltage controlThe proposed wind turbine fed fixed speed induction generator is evaluated and simulated using MATLAB/SIMULINK environment with UPQC and DVR under asymmetric faults
Arbeidsmarketing voor flexibele medewerkers | influx14Recruiting Academy
(Door Annemarie Stel | Wervingsvisie.nl
Bij de vraag hoe organisaties zichzelf en het werk binnen de organisatie ‘verkopen’, gaat het lang niet meer alleen om het aanspreken van de traditionele ‘vaste medewerkers’. Een veelheid aan tijdelijk en/of flexibel personeel, zoals uitzendkrachten, payrollers, ZZP’ers, interimmers, maakt de ‘workforce’ steeds veelvormiger, evenals het soort werk: van vaste baan tot kortere of langere klus.
Deze presentatie is te downloaden op de site van Recruiting Academy, via: http://www.recruitingacademy.nl/influx-vakevent-voor-arbeidsmarktprofessionals/
Enhancing phase margin of ota using self biasingelelijjournal
In this paper, a new adaptive biased low voltage cascode current mirror with high input/output swing is presented. This advantage is achieved using a self-biasing transistor and compensation resistor. The new structure profits from better input dynamic range and lower supply voltage without frequency response limitation and increasing input impedance. Also, the proposed current mirror is incorporated in folded cascode amplifier in order to enhance its phase-margin. The simulation results in 0.18 μm CMOS technology confirm the theoretical analysis and exhibits 478μA linear input/output current swing and a
phase-margin enhancement of 12o for the proposed current mirror and amplifier compared to the conventional circuits, respectively
This document summarizes the results of a study on identifying the weakest branch in a radial distribution network with composite loads using distributed generation. The study tested the approach on a 33-node, 12.66 kV radial distribution system. The reactive loading index technique was used to identify the weakest branch for various levels of distributed generation placed at the optimal node. It was found that branch 5 was the weakest up to 30% distributed generation capacity, after which branch 27 became the weakest as the distributed generation level increased to 100% of the total load. The results provide guidance on how the weakest branch may change with different amounts of distributed generation on the network.
Applicability of Error Limit in Forecasting & Scheduling of Wind & Solar Powe...del2infinity Energy
A Technical paper on ‘Applicability of Error Limit in Forecasting & Scheduling of Wind & Solar Power in India’’ by Abhik Kumar Das at India SMART GRID Week 2017 organised by India Smart Grid Forum & Government of India at Manekshaw Centre, New Delhi.
The document discusses using regression models and k-means clustering to improve voltage stability in power systems. It begins by introducing the concepts of voltage stability and issues that can cause instability. Regression models are then presented as a way to model the relationship between pre-disturbance operating points and critical voltage stability margins. The k-means clustering algorithm is also described as a method to group inputs and reduce dimensionality for improved generalization. Results show that regression models can approximate stability margins and k-means clustering effectively handles large amounts of data by determining an optimal number of cluster centers. The proposed approach is concluded to analyze the most critical post-disturbance stability margin through regression and clustering techniques.
Short-term load forecasting with using multiple linear regression IJECEIAES
This document discusses short-term load forecasting using multiple linear regression. It summarizes the research method used, which involves developing a multiple linear regression model to predict electrical load based on variables like temperature, humidity, day of week, and previous load data. The model is trained on historical load and weather data from New York City over 9 years. Testing shows the model can predict load a day ahead with 5.15% mean absolute percentage error. Regression coefficients, t-statistics, and p-values indicate the trained model explains about 90% of the variation in load and the predictors are statistically significant. An example day-ahead hourly load forecast is provided for June 25, 2019.
This document proposes an artificial neural network and fuzzy logic controller tool for online voltage stability monitoring and estimating reactive power (VAR) support needs in deregulated power systems. The tool uses bus voltage angles and reactive power loads as inputs to the ANN, which then outputs the voltage stability margin and voltage stability factor of the most vulnerable bus. The ANN is trained offline using patterns from continuation power flow simulations. The tool can estimate stability margins and determine minimum VAR support for different system conditions and contingencies in deregulated markets. It has been tested on IEEE 14 bus and 30 bus systems.
The document presents a multi-objective optimization model for allocating thyristor-controlled series capacitors (TCSCs) in power systems with wind power and load randomness. It first describes existing literature on modeling renewable energy and load uncertainty and optimizing power system objectives. It then introduces a method to generate and reduce scenarios for wind power and load. Next, it establishes a multi-objective optimization model with available transmission capacity and voltage stability as objectives. Finally, it proposes an improved multi-objective particle swarm optimization algorithm to solve the established model.
Evaluation of electrical load estimation in Diyala governorate (Baaquba city)...IJECEIAES
The evaluation of electrical load estimation is requisitely of any electrical power system. This manner is needed for system obligation, economical distribution and maintenance time of electrical system. In this paper, we propose electrical load estimation method based on fuzzy inference system which gives accurate results for estimated loads in Iraq (Diyala governorateBaaquba city). And it can assist the electrical generation and distribution system that depends on important parameters (temperature, humidity and the speed of the wind). By considering the parameters temperature, humidity and the speed of the wind. These parameters are applied as inputs to the fuzzy logic control system to obtain the normalize estimated load as output by electing membership functions. It is exceptionally valuable to form a choice by taking into consideration these assessed readings that come to from the proposed FIS that displayed in this paper with precision of 0.969 from the real stack request.
Reactive power aspects in reliability assessment of power systemsIAEME Publication
This document discusses reactive power aspects in power system reliability assessment. It begins by noting that while reactive power plays an important role in operations, it is seldom considered in reliability evaluations. It then proposes several ideas:
1) Define new reliability indices to represent the effects of reactive power shortages on reliability, separate from real power shortages.
2) Consider failures of reactive power sources and incorporate reactive power limits determined by generators' real power outputs.
3) Propose a reactive power injection technique to determine possible shortages and locations.
4) Modify an IEEE test system to illustrate the proposed approach and provide planners/operators information on real and reactive power management.
Evaluation of wind-solar hybrid power generation system based on Monte Carlo...IJECEIAES
The application of wind-photovoltaic complementary power generation systems is becoming more and more widespread, but its intermittent and fluctuating characteristics may have a certain impact on the system's reliability. To better evaluate the reliability of stand-alone power generation systems with wind and photovoltaic generators, a reliability assessment model for stand-alone power generation systems with wind and photovoltaic generators was developed based on the analysis of the impact of wind and photovoltaic generator outages and derating on reliability. A sequential Monte Carlo method was used to evaluate the impact of the wind turbine, photovoltaic (PV) turbine, wind/photovoltaic complementary system, the randomness of wind turbine/photovoltaic outage status and penetration rate on the reliability of Independent photovoltaic power generation system (IPPS) under the reliability test system (RBTS). The results show that this reliability assessment method can provide some reference for planning the actual IPP system with wind and complementary solar systems.
ENHANCING RELIABILITY BY RECONFIGURATION OF POWER DISTRIBUTION SYSTEMS CONSID...Suganthi Thangaraj
The paper describes an effective method to reconfigure a power distribution system using optimization techniques. Here genetic algorithm is used for the reconfiguration to enhance reliability and to reduce losses. The reliability at the load points is evaluated using probabilistic reliability approach. For finding minimal cut sets and losses different algorithms are used. To maximise the reliability and to reduce the losses, the status of the switch is controlled using genetic algorithm. The effectiveness of the system is tested in 33 bus distribution system.
Reduce state of charge estimation errors with an extended Kalman filter algor...IJECEIAES
Li-ion batteries (LiBs) are accurately estimated under varying operating conditions and external influences using extended Kalman filtering (EKF). Estimating the state of charge (SOC) is essential for enhancing battery efficiency, though complexities and unpredictability present obstacles. To address this issue, the paper proposes a second-order resistance-capacitance (RC) battery model and derives the EKF algorithm from it. The EKF approach is chosen for its ability to handle complex battery behaviors. Through extensive evaluation using a Simulink MATLAB program, the proposed EKF algorithm demonstrates remarkable accuracy and robustness in SOC estimation. The root mean square error (RMSE) analysis shows that SOC estimation errors range from only 0.30% to 2.47%, indicating substantial improvement over conventional methods. These results demonstrate the effectiveness of an EKF-based approach in overcoming external influences and providing precise SOC estimations to optimize battery management. In addition to enhancing battery performance, the results of the study may lead to the development of more reliable energy storage systems in the future. This will contribute to the wider adoption of LiBs in various applications.
MODELING AND OPTIMIZATION OF PIEZOELECTRIC ENERGY HARVESTING adeij1
In this paper, the modeling, optimization and simulation results of the piezoelectric energy harvesting using bond graph approach are presented. Firstly, a lightweight equivalent model derived from the bond graph is proposed. It’s a comprehensive model, which is suitable for piezoelectric seismic energy harvester investigation and power optimization. The optimal charge impedance for both the resistive load and complex load are given and analysed. Finally a bond graph approach is proposed to allow optimization of the extracted energy while keeping simplicity and standalone capability. The proposed model does not rely on any inductor and is constructed with a simple switch. The power harvested is more than twice the conventional technique one on a wide band of resistive load. The bond graph model is valid close to the analysed mode centre frequency and delivers results compared to experimental and analytical data. Furthermore, we also show that the harvester can be electrically tuned to match the excitation frequency. This makes it possible to maximize the power output for both linear and non-linear loads.
Harmonic assessment on two photovoltaic inverter modes and mathematical model...IJECEIAES
Power quality is a crucial aspect of designing a large-scale photovoltaic power plant, particularly regarding harmonics caused by inverter switching. This research aimed to analyze harmonics in a system using electrical transient analyzer program (ETAP) Power Station 20.5.0 to uncover the effect of irradiance on the inverters’ power quality running at 85% and 100% power factors. We analyzed both voltage and current total harmonic distortion (THDi and THDv) from the simulation and compared them with the mathematical model. Moreover, we analyzed the effect of changes in irradiance level on harmonics and reactive power penetration, which influenced power losses in transformers and cables. Inverters at 85% power factor experienced an increase in THDi, whereas those at 100% power factor decreased. Inverters with 85% power factor experienced more frequent switching, causing more prominent distortion. The magnitude of THDv increased proportionally with the rise of irradiance level. Inverters at 85% had a higher THDv value because of the excessive reactive power compensation when irradiance rose. Irradiance level had an inverse relationship with system losses since high irradiance levels led to lower losses as less power was required through transmission lines and transformers. Moreover, losses at 85% power factor were higher since the high harmonics caused additional losses.
Short Term Electrical Load Forecasting by Artificial Neural NetworkIJERA Editor
This paper presents an application of artificial neural networks for short-term times series electrical load
forecasting. An adaptive learning algorithm is derived from system stability to ensure the convergence of
training process. Historical data of hourly power load as well as hourly wind power generation are sourced from
European Open Power System Platform. The simulation demonstrates that errors steadily decrease in training
with the adaptive learning factor starting at different initial value and errors behave volatile with constant
learning factors with different values
Maximum Loadability Enhancement with a Hybrid Optimization MethodjournalBEEI
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FUZZY NUMBERS BASED ON ENERGY INDICATORS OF RELIABILITY POWER SYSTEM
1. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 5, No 2, May 2016
DOI : 10.14810/elelij.2016.5205 51
FUZZY NUMBERS BASED ON ENERGY
INDICATORS OF RELIABILITY POWER
SYSTEM
1
Nadheer A. Shalash and 2
Abu Zaharin Ahmad
1
Faculty of Engineering of Electrical power techniques
Al-Mamon University college,
Baghdad, Iraq
2
Faculty of Electrical and Electronics Engineering
University Malaysia Pahang,
26600 Pekan, Malaysia
Abstract
This paper presents the approach of fuzzy numbers for reliability calculation of electrical energy indices
and compared to an analytical method. In this paper, the fuzzy numbers which are represented by
triangular fuzzy numbers are used to evaluate the load duration curve and the probabilities capacity
generators that are in services, in term of the expected energy not supplied (EENS), loss of energy
expectation (LOEE) and the energy index of the reliability (EIR). A case study based on the Malaysia
distribution network (DISCO-Net) is carried out.The proposed method shows a simple implementation and
the results seem to be a good approximation to the analytical approach.
Keywords
Electrical energy indice; fuzzy numbers; daily load; Probability.
1. INTRODUCTION
Recently, many applications of the fuzzy numbers approach to electric power system engineering
have been proposed. One of these applications is assessed on reliability generation based on the
loss of energy indices. Reliability of the generated power system is afflicted with the load curve
characteristics, peak duration and variety between levels of the peak at each hour, day and month
of each season of a year. Various kinds of customers might have different load curve charts. The
most frequent for electrical loads are for residential, commercial and industrial, which isfor each
load curve usually contains a characteristic chart. Probability based models have already been
advanced for precisely reflects the stochastic nature of generators behavior and determines its
reliability interpretation [1-2]. As a result of the increased demand powers, a small separated
system is not able to provide a power with sufficient generation control and an acceptable level of
2. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 5, No 2, May 2016
52
reliability at hierarchical level I (HL-I). This includes the ability of the generation to meet the
total system load requirement [3] and to have the reserve margin capacity in order to serve for
planned and forced outage events. It is also must be able to accurately meet up with the large
fluctuations in the load from the result of a different quantity of power users[4, 17].
Power system reliability can be divided into two aspects, i.e., adequacy and security. System
adequacy is related to the existing of appropriate generators within the system to cater the
demand or the operational constraints and also to have an excess capacity to cater for planned and
forced outage events that depended on the area under the load duration curve. In this paper, most
widely used indices in electrical energy is presented, i.e., Loss of Energy Expectation (LOEE),
Expected Energy Not Supplied (EENS) and the Energy Index of Load Reliability (EIR).
In [5],has presented a new fuzzy operationfor the area under the load duration curve model for
evaluating reliability indices of composite power systems based on probability and fuzzy set
methods.Meanwhile, in [6] has used fuzzy load description in generation, transmission power
system reliability that using Monte Carlo method. A new hybrid approach to evaluate a
generation system reliability using a fuzzy clustering approach in modeling the loads has been
presented in [7]. Then, in [8] had proposed a genetic algorithm guided by fuzzy numbers to
evaluate the power system reliability.
Hence, motivated by the reviews, this paper is tend to proposein the application of a fuzzy
numbers approach to energy indices of power system based on the LOEE , EENS and EIR
analysis. The proposed technique is then tested by using Malaysia distribution network (DISCO-
Net) in MATLAB environment. The test results show by comparing the proposed technique with
analytical method in order to help the engineers to measure and make decisions for assessment
reliability power system.
2.ENERGY RELIABILITY INDICES
The most common methods used for reliability evaluation, are based on the loss of load or energy
approach. In this method, the suitability index that describes generation reliability level is loss of
energy expectation.It can be calculated the area under the load duration curve.It also indicates the
time in which the load is more than available generation and can be used to calculate an expected
energy not supplied [9,19]. In [10], By Billinton and Li (1994), The basic expected energy
curtailed concept can also be used to determine the expected energy produced by each unit in the
system and therefore provides a relatively simple approach to production cost modelling.
ܵܰܧܧ = ∑ ܲሺܥ௦ሻୀௌ (1)
Where, S: set of all possible system states associated with loss of load, Cs: Capacity in service,
Dns: demand not supplied of state i.
The probable energy curtailed is obtained as a production of a probability of capacity in outage
(Pi) and the energy curtailed by capacity in outage (Ei). The sum of these givesthe total loss of
energy expectation (LOEE) [9,11,19].
i
n
i
i PELOEE ∑
=
=
1
(4)
3. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 5, No 2, May 2016
53
After that, it can be normalized the loss of energy expectation by using the total energy under the
load duration curvedesignated as E in Equation (3).
∑
=
=
n
i
ii
E
PE
LOEE
1
% (3)
Future electrical power systems may be energy limited rather than power or capacity limited, so
we will study the ratio between the probable load energy curtailed because of reduced capacity
because of specific capacity in outage and the total energy under the load duration curve can be
defined as an energy index of unreliability. The energy index of reliability (EIR) is then as
follows [11]:
%1 LOEEEIR −= (4)
3.FUZZY NUMBER
The arranging of fuzzy numbers plays an important role in decision making and optimization in
power system reliability. The fuzzy approach must be derived before an action is taken by an
engineer. In this paper, the special class of fuzzy numbers for load called triangular fuzzy
numbers is used [12,16].The fuzzy set G is called a normal fuzzy set. A fuzzy number is a fuzzy
method in the load that is both convex and normal. A type of fuzzy number of the load can be
characterized by a triangular membership function parameterized by a triplet (L1, L2, L3), as
shown in Fig. 1 [13].
Figure 1. Triangular membership function
The membership function is defined in mathematical form as follows:
4. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 5, No 2, May 2016
54
ߤܮሺݔሻ =
ە
ۖ
۔
ۖ
ۓ
0 ݔ < ܮଵ
௫ିభ
మିభ
ܮଵ ≤ ݔ ≤ ܮଶ
యି௫
యିమ
ܮଶ ≤ ݔ ≤ ܮଷ
0 ݔ > ܮଷ
(5)
Where xisa load duration curve.
4.PROPOSED METHOD
In this section, the proposed approach to electrical energy indicesevaluation is presented which
takes the load duration under curve with probabilities capacity outage using a new fuzzy
evaluation sheet.As an example, a generation system consists of 3× 20 MW, that means, the
estimation is based on 4 selected capacity outage as namely the generation 0, 20, 40 and 60 MW
with identical weights of each state is w1, w2, w3 and w4 respectively, where wi ∈ [0,1] and i =
1, 2, 3 and 4. The value of the weight will be determined the degree of membership that
obedience to load levels (Ls) and the probability (P1, P2, P3and P4) as shown in Fig. 2.
Figure 2. Triangular membership function for load level
Each fuzzy load number is defined by three values of load to usetriangular fuzzy numbers [14,16]
comprehensive effects of transmission line [18]. In Table I, The fuzzy numbers offered ten
satisfaction levels in addition, area percentage of loads and the maximum degree of membership.
Fainlly, the fuzzy evaluation sheet has four state (C1,C2,C3,C4) for capacity in service as shown
in Table II.
1
0.5.5
0
Load(%)
The degree of membership
P1 P2 P3 P4
5. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 5, No 2, May 2016
55
Table I
Level of Load and Their Identical Degree of Load
Level of Load
Degree of Load
(Ls)
Maximum degree of
membership
100% load 100% 1
90% load 81% – 99% 0.9
80% load 71% – 80% 0.8
70% load 61% – 70% 0.7
60% load 51% – 60% 0.6
50% load 41% – 50% 0.5
40% load 31% – 40% 0.4
30% load 20% – 30% 0.3
20% load 1% – 19% 0.2
0% load 0% 0.0
REMIND ME LATER
Table II New Fuzzy Evaluation Sheet
The degree of satisfaction of the load (Ls) is calculated by equation (6) :
(6)4321
4321 %40*%30*%20*%10*
dddd
dddd
Ls
+++
+++
=
Capacit
y in
service
L
o
a
d
s
We
igh
ts
Load levels Degre
e of
Satisf
action
(Ls)
Fuzz
y
load
(Fl)
Pr
ob
abi
lity10% 30% 60% 100%
C1 =0 W1 d1 d2 d3 d4 P1
C2 =20 W2 P2
C3 =40 W3 P3
C4 =60 W4 P4
Capacit
y in
service
L
o
a
d
s
We
ight
s
Load levels Degre
e of
Satisfa
ction
(Ls)
Fuzz
y
load
(Fl)
Pro
bab
ilit
y10% 30% 60% 100%
C1 =0 W1 d1 d2 d3 d4 P1
C2 =20 W2 P2
C3 =40 W3 P3
C4 =60 W4 P4
6. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 5, No 2, May 2016
56
Where, dk Є [0,1] is a degree of fuzzy load and 1 ≤ k ≤ 4, The fuzzy load (Fl) for every state can
be calculated by Equation (7):
(7)
Where, Load I = load demand, which requires an evaluation of the determined capacity in service,
including larger values of capacity in service.
The demand not supplied (Dns) it is equal to energy curtailed by capacity in service. When the
fuzzy load applied to implement the (Dns) this will result into the Equation (8):
Dns = (ILT - FI)*h = Ei - FI*h (8)
Where, ILT : total load demand under the load duration curve, h: the duration of load power in
hours.
The equations in section II above, i.e (1), (3) and (4) were used to assess losses of energy indices
without fuzzy, in the subsequent Equations (9), (10) and (11), fuzzy load duration curve shall be
used to evaluate these indices.
EENS = ∑ p୧୧Єୱ ሺCୱሻ ∗ ሺE୧ − FI ∗ hሻ (9)
LOEE = ∑ EENS୧Єୱ (10)
EIR = 1 −
(11)
Figure 3: Single line diagram of Malaysia network of DISCO-Net power system
load* iiLsFl =
7. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 5, No 2, May 2016
57
Table III
The data of generating units and transmission line (Network of DISCO-Net)
Parameters No. λ(occ./year)
µ
(hrs)
Unit
failure
probab.
Unit
success
probab.
G1 2 2 98 0.1 0.9
DG 1 2 98 0.1 0.9
L1, L2, L3, L4, L5 2 2 98 0.1 0.9
L6, L7, L8, L9, L10 3 2 98 0.1 0.9
L11, L12, L13, L14 2 0.03 98 0.2 0.8
L17, L18, L19, L20 3 0.09 98 0.2 0.8
L21, L22, L23, L24 3 0.2 0.5 0.2 0.8
L27, L28, L29 2 0.28 0.5 0.2 0.8
L31, L32, L33, L34 2 0.23 0.5 0.2 0.8
L35, L42, L41 2 0.01 0.5 0.2 0.8
L15, L16, L25, L26 2 0.09 0.5 0.2 0.8
L39, L40 2 0.15 0.5 0.2 0.8
L30, L38, l37 2 0.25 0.5 0.2 0.8
5. DESCRIPTION OF TEST SYSTEM
The step down substation (in Malaysia is called main intake substation) is connected to the grid at
nominal voltage of 132kV. The maximum 3-phase and 1-phase-to-ground fault currents at the
source are illustrated in Fig. 3 which means that on a 3-phase solid fault of the 132kV bus, the
fault current, which is contributed by the source, is 20kA and 15kA on a single-phase to ground
fault. The 132kV is stepped down to 11kV using 2x30MVA transformers and to 33kV using
2x45MVA transformers whose parameters are also illustrated in Fig. 3 (Network of DISCO-Net)
[15]. This system has 33 buses with a 32 load bus, 45 transmission lines and 2 generating units
2x75MW. The total installed generating capacity is 150MW and the peak load of the system is
120MW. The data of generating units are given in Table III.This system was selected as a case
study to implement the developed coding in order to analysis and determine electrical energy
indices by fuzzy numbers and compared to an analytical method.
8. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 5, No 2, May 2016
58
Figure 4: Load duration curve for DISCO-Net
Table III: Analytical method to Calculate EENS with unit 1
Table IV Analytical Method To Calculate Eens With Units 1&2
Capacity
out service
(MW)
Capacity in
service
(MW)
Probability
Energy
MWh
EENS
0 150 0.5314 0 0
25 125 0.059 0 0
50 100 0.00656 2440 16.0064
75 75 0.000729 3940 2.87226
100 50 0.000081 4440 0.35964
125 25 0.000009 5940 0.05346
150 0 0.000001 8440 0.00844
Capacity out
service (MW)
Capacity in
service (MW)
Probability
Energy
MWh
EENS
0 75 0.729 3940 2872.26
25 50 0.0891 4440 395.604
50 25 0.009 5940 53.46
75 0 0.001 8440 8.44
9. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 5, No 2, May 2016
59
Figure 4. Load duration curve for DISCO-Net
Table VI New Fuzzy Evaluation For Disco-Net
6. RESULT AND DISCUSSION
First, in this study estimate, load duration curve for DISCO-Net is shown in Fig. 4. The total
required energy in this duration is 8440 MWh. If there is no generation in the system, the
expected energy not supplied would be 8440 MWh when the system has 75 MW.Table IV is
shown an analytical method for the EENS with Unit 1, the value of expected energy not supplied
is equal (2872.26 +395.604+53.46+8.44) and the expected energy by unit (1) = 8440 – 3329.764
= 5110.236 MWh. From these results the energy index of the reliability EIR by unit (1) is
0.605478. The assistance from unit (2) can be obtained by adding 75 MW to the generation units
10. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 5, No 2, May 2016
60
of the Table IV and resulting the expected energy not supplied for units (1) and (2) integrated
(see Table V).In this case, the total EENS =19.3 and the expected energy by unit (2) is 5090.933
MWh.Finally, we can calculate EIR for the system using Equation(4), i.e.,EIR=1-(19.3/8440) =
0.9977132.
Then, second proposedof the fuzzy number to compare the calculating results of the reliability
energy indexes with analytical method.The fuzzy number has one membershipconsidering
triangular fuzzy numbers for load duration curve shown in Fig.5.
For example, the column weights value in the Table V is obtained by simply dividing load with
capacity in service, i.e.,80/100 = 0.8. This value 0.8, will then determine the degree of
membership corresponding to the probabilities levels, from the results obtained in Table VI, the
values, 0,0,0,0, 0.4,0.56,0.79 denotes the load level values at L1-L7 respectively. The values of
energy and EENS were calculated with equations 6 and 7 which are the fuzzy load set that uses
the central of the area. From table IV below, the same simulation was applied to the subsequent
load levels, the EENS for each stage obtained were summed up to get 17.067 otherwise referred
to herein as defuzzification value, thus denoting the expected energy not supplied.
From this result, the energy index of the reliability EIR is 0.997977 derived from equation 9.
Conclusively, it is clearly shown that the result obtained with the use of EIR by fuzzy as energy
indices assessment is close to the one derived when analytical method was used for same
assessment.
7.CONCLUSION
This paper has been presented the application of a fuzzy numbers method to evaluate energy
reliability indices based on a load duration curve and probabilities the capacity generators in
service and compared with an analytical method in term of the expected energy not supplied and
the energy index of the reliability for each state. It seems to be more near compared to results
used in analytical approach.Therefore, this paper can help engineers to measure the reliability
power system and make decisionsfor future process generation expansion planning.
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