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International Review on
Modelling and Simulations
October 2013
(Vol. 6 N. 5)

     Part A - Part B

    An Enhanced Cascaded Topology of Non-Isolated Bidirectional DC-DC Converter with Switched Coupled Inductor

    by Buvana Devaraju, Jayashree Ramasubramanian


    Abstract - Today bidirectional DC-DC converter is used as energy storage system, which have high efficiency technology because single converter can be able to perform both step up and step down conversion operation. The bidirectional converter consists of isolated and non-isolated transformer which appears depending on the applications. During the step up and step down operation, the converter causes current stress through the close switch or the voltage stress across the open switch. Hence, the winding loss is occurred due to the presence of magnetic storage elements such as leakage or parasitic inductance’s. These problems are overcomed by the proposed topology i.e., an enhanced cascaded topology of non-isolated Bidirectional DC-DC converter for refining the effectiveness of the conversion. The enhanced topology is operated by soft- switching, continuous inductor current and fixed switching frequency. In the proposed DC-DC converter topology, the coupled inductor performance has been improved by the switched coupled-inductor. The cascading purpose of the proposed topology is to regulate the conversion accuracy of the non-isolated Bidirectional DC-DC converter. As the cascading is one of the wide area techniques to operate the DC-DC converter with reduced switching stress and voltage spikes across the switch during turn OFF. In this proposed topology, multi level enhanced cascading is adopted. The proposed converter is implemented in MATLAB working platform and the output performance is analyzed.

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    Keywords: DC-DC Converter, Switched Coupled Inductor, ZVS, ZCS.


    Simulation & Implementation of a New Single-Inductor Dual-Output Resonant Step down/up Converter

    by K. Sundararaman, M. Gopalakrishnan, S. Ezhilarasi


    Abstract - This paper presents a new non-isolated, single-inductor, dual-output resonant step down/up converter. The outputs are fed power from the same supply one after another. The output voltages could be more than or less than the supply voltage and both buck or boost outputs are possible. Soft switching is achieved and losses are reduced. Steady state analysis of the converter is done. The primary output is closely regulated by common-mode frequency control and the auxiliary output is controlled by differential mode PWM control. A comprehensive simulation of the converter with line and load variations is done and the results are in agreement with the analysis. Some typical hardware results are also presented as a validation. The topology is scalable to additional outputs as well.

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    Keywords: DC-DC Converter, Multi-Output, Resonant Converter, Single-Inductor, Soft-Switching.


    Selective Harmonic Elimination PWM for Cascaded Multilevel Inverter Based Genetic Algorithm and Newton Raphson: A Comparison Study

    by Gamal M. Hashem, Ramy M. Hossam


    Abstract - The Selective Harmonic Elimination Pulse Width Modulation technique (SHEPWM) is widely used for eliminating pre-selected lower order harmonics in multilevel inverters (MLI) output voltage with controlling the fundamental voltage component. The problem of roots solving of the set of transcendental nonlinear harmonic equations derived by Fourier analysis is addressed in many recent researches. The Newton Raphson (NR) method is limited used in case of multilevel inverter controlled by SHEPWM, due to the transcendental nature of the system set of equations and dependency of roots initial values. Modern optimization techniques such as Genetic Algorithm (GA) optimization are widely used in case of MLI controlled by SHEPWM. The main problem when using GA is how to find the switching angle patterns for a wide range of the modulation index (M). Which they eliminate pre-selected lower order harmonics and controlling the fundamental voltage component with minimum Total Harmonic Distortion (THD). In this paper a comprehensive study to obtain the required switching patterns which satisfy elimination pre-selected lower order harmonics at minimum THD from cascaded MLI output voltage controlled by SHEPWM was performed. The performance of cascaded multilevel inverter controlled by SHEPWM is compared based on calculating the required switching patterns using NR and GA methods. A significant improve in the obtained solution sets in a wide range of M in GA is achieved. In particular, it is shown that there are new solution sets which haven't been previously reported in literatures. Selected simulation and experimental results for 5, 7, 9 and 11 MLIs were reported to verify and to validate the theoretical findings.

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    Keywords: Genetic Algorithm, Newton Raphson, Multilevel Inverter, SHEPWM.


    Compact Cascaded H-Bridge Multilevel Inverter with Single DC Source for Pure Electric Vehicle

    by S. Veerakumar, A. Nirmal Kumar, T. Rajesh


    Abstract - The electric vehicle with compact inverter size using modified H-bridge inverter with modified topology has proposed. The modified topology use single DC source and with proposed SSVPWM. The SSVPWM was generated using sampled reference frame algorithm this algorithm used only sampled amplitude of reference phase voltages. This reduces computation time in DSP controllers where conventional algorithm requires more machine cycle to execute. The inverter output is fed to induction motor which propels the rear wheel. The sudden acceleration and de-acceleration will increase the switching stress and harmonics in the output. The neuro fuzzy optimization is used to mitigate the harmonics and bring down to the EN 50160 gride code. This model has been developed successfully using dsPIC with 5-level H-bridge inverter and has been tested in 2.2 Kw induction motor.

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    Keywords: Space Vector Pulse Width Modulation (SSVPWM), Artificial Neuro Fuzzy Inference System (ANFIS), Selective Harmonic Mitigation Pulse Width Modulation (SMHPWM), Selective Harmonic Pulse Width Modulation (SHPWM), Total Harmonic Distortion (THD), Fast Fourier Transform (FFT), Interrupt Service Subroutine (ISR).


    Implementation of Neuro-Fuzzy Controller to Reduce Output Voltage Ripple of KY Boost Converter

    by S. Karthikumar, N. Mahendran, S. Sriraman


    Abstract - KY boost converter a non-isolated DC-DC boost converter is a recent invention which operates in CCM (Continuous Conduction Mode) which is known for low output voltage ripple with fast settling time. In this article a Neuro-Fuzzy controller is designed using Simulink® to reduce the OVR (Output Voltage Ripple) and to improve settling time of the converter output. The simulation and experimental results obtained exhibit a reduction in voltage ripple from few milli volts of existing system to micro volts and the settling time is also improved in milli seconds with high efficiency.

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    Keywords: DC-DC Converter, KY Boost Converter, Neuro-Fuzzy Control, OVR.


    A Common Mode Voltage Reductions for Three Phase Coupled Inductor Inverter Using Multi-Carrier Interleaved PWM Strategies

    by C. Bharatiraja, S. Jeevananthan, S. Raghu, V. Arvind, A. Sameer


    Abstract - This work presents multi-carrier interleaved PWM strategies to control common mode voltage (CMV) in three phase coupled inductor inverter (CII). The proposed scheme has the feature of reduced number of switches with higher output voltage level. The major problem in the coupled inductor inverter (CII) topology is power loss in inductor that is related to the magnitude of current ripple in the winding. The proposed multi-carrier interleaved PWM technique is easy to implement when compared to other PWM techniques. The additional advantage is reduction of the current ripple in inductor. The minimization of current ripple in inductor winding leads to the reduction in the common mode current participation in the (Y-Δ) connected induction motor. The common mode voltage is represented as the integration of the common mode current in each phase. The multi-carrier interleaved PWM consists of the continuous and discontinuous modes of operation. By choosing the high effective switching state with the help of Discontinuous PWM technique for inductor winding, the common mode voltage (CMV) can be reduced without degrading the performance of the inverter. The proposed scheme is applied for three-phase coupled inductor inverter (CII) to obtain the five level output. The benefit of these proposed switching strategies is reduction of the common mode voltage in the range of +Vdc/12. The simulation with 1HP induction motor drive system is set-up in MATLAB and same result is validated effectively by hardware-FPGA SPARTAN-3E processor.

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    Keywords: Coupled Inductor Inverter (CII), Multi-Carrier Interleaved PWM Technique, Common Mode Voltage (CMV), Discontinuous PWM (DPWM).


    Current Control Strategy for Grid Connected Photovoltaic Inverter via LCL Filter

    by Rihab Mahjoub Essefi, Mansour Souissi, Hsan Hadj Abdallah


    Abstract - This paper presents a method to design a control system for grid connected photovoltaic inverter which has an LCL type filter to suppress the output current total harmonic distortion (THD). In this control system, three linear voltage and current controllers were used in a cascade configuration in order to reduce the complexity of the system. Those controllers regulate the current injected to the grid in a synchronous reference frame which transforms ac variables into dc quantities and thus possibility of applying simple PI regulators. Simulation results, using Matlab/simulink, presented for this strategy confirm the effectiveness of the control scheme in both transient and steady state operation.

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    Keywords: Photovoltaic Inverter, LCL Filter, Linear Controller, DQ Transformation, Grid Synchronization.


    A New Asymmetric Duty-Cycle Control for a ZVS Self-Oscillating Half-Bridge Inverter

    by Belloumi Hamed, Kourda Férid


    Abstract - In this paper, a simple power control scheme for a constant frequency self-oscillating inverter with a variable duty cycle is proposed. The proposed topology, based on the half-bridge series resonant inverter, can achieve a stable and efficient Zero-Voltage-Switching (ZVS). As a consequence, the converter efficiency is significantly improved. This novel technique consists in injecting a DC control current through a saturable core providing a variable asymmetric control as a function of the injected current; we can therefore control and regulate the output power while maintaining the switching frequency close to the resonant one. The control principles of the proposed method are described in detail and its validity is verified through simulated and experimental results on 750 W with constant frequency variable power.

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    Keywords: Saturable Transformer with DC Control Current, Self-Oscillating Inverter, Asymmetrical Control, ZVS (Zero-Voltage-Switching).


    Dual Z-Source Three level Inverter Topology with Triplen Harmonic Elimination Employing Clamping Capacitor for Impedance Network for Open End Stator Winding Induction Motor

    by C. L. Kuppuswamy, T. A. Raghavendiran


    Abstract - In open end stator winding three phase induction motor the two ends of all the phases of stator windings are connected to separate supplies. Open-end winding motors require either harmonic filters or isolation transformers to prevent currents of the triplen harmonic order flowing in the motor phases and the semiconductor devices. Separate dc supply is used for each inverter to block the flow of third harmonic currents. Z-Source Inverter will act as a booster inverter and also due to the presence of source impedance network, it provides ride through shoot through faults. A novel configuration of three level Neutral Point Clamped (NPC) Multi level Inverter with source impedance network, in which impedance network is formed by using the capacitors of the NPC inverter is proposed in this paper. Therefore the numbers of capacitors are reduced and voltage unbalancing of capacitor can be minimized. The proposed configuration offers reduced size and better throughput. The simulation results for the same are presented in this paper.

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    Keywords: Open End Winding Induction Motor, Z-Source, Impedance Network, Triplen Harmonic Elimination.


    Algebraic Model for Predicting the Hydraulic Behaviour of an Open Self-Ventilated Electrical Machine

    by M. Satrústegui, M. Martínez-Iturralde, A. Rivas, J. C. Ramos


    Abstract - This paper describes an algebraic model for predicting the air flow-rate in the cooling system of an open self-ventilated machine. The method is easily applicable to any type of air-cooled electrical machine. The air flow-rates in different areas of the machine as well as the head losses of the hydraulic system were obtained, and the results were compared with a more detailed model developed with Computational Fluid Dynamic (CFD) techniques. Moreover, a sensitivity analysis was carried out in order to compare the different topologies of the machine studied.

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    Keywords: Algebraic Model, Hydraulic System, Electric Machines, CFD.


    Modeling and Simulation of BLDC Motor for Minimizing the Cogging Torque, Harmonics and Torque Ripples

    by M. Arun Noyal Doss, V. Ganapathy, V. Marthandan, D. Mahesh


    Abstract - This paper proposes an improved methodology to minimize the cogging torque, harmonics and torque ripples in Brushless DC (BLDC) motor. First off, the cogging torque is reduced by designing the BLDC motor with bifurcated active surface area using Finite Element Analysis (FEA). The harmonics and torque ripple is minimized using PI and Fuzzy controllers. These controllers are analyzed to bring out an optimal solution. The effectiveness and flexibility of the individual techniques of proposed control method is verified through simulations [Matlab Simulink].

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    Keywords: Brushless DC Motor (BLDCM), Cogging Torque, Fuzzy Controller, Stator Current Torque Ripple.


    Simulation of Electromagnetic Interference and Its Mitigation in an Induction Motor Drive

    by Nisha P. V., Sindhu T. K., Elizabeth P. Cheriyan


    Abstract - This paper analyses the EMI issues associated with an induction motor drive circuit using IGBTs. The high frequency equivalent circuit of IGBT is modelled in MATLAB software and the waveforms plotted are corroborated with data sheet waveforms. A variable speed induction motor drive with six such IGBT sub system as the switching units is developed. The conducted EMI voltage is obtained with a Line Impedance Stabilization Network (LISN) between the EMI source and the power supplies. The measured values are compared with CISPR conducted emission limits. A filter is designed to eliminate the interference due to conducted EMI.

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    Keywords: CISPR Limits, Conducted EMI, Electromagnetic Interference (EMI), Line Impedance Stabilization Network (LISN).


    Grid Connected CSP-ORC Plants for Residential Application

    by A. Amoresano, P. De Sio, A. Gimelli, G. Langella, S. Meo


    Abstract - In this paper the thermodynamic and electrical optimization of small power Concentrated Solar Power plants is presented. The plant is based on an Organic Rankine Cycle working with thermal oil as primary fluid. This study is part of Italian Research project “ Themodynamic Solar Plants in Urban Areas” aimed to develop small scale CSP plants to be installed on buildings roofs in residential areas or on factory sheds, in order to not subtract land to farming. Case studies were performed for capture surfaces of about 100 square meters and electric power output of approximately equal to 10 kWe. Through thermodynamic optimizations, results were compared in terms of global electric efficiency with the same electrical power, by varying the working fluid in the power circuit. For what concerns the solar circuit it has been considered composed of parabolic through concentrators. Electric design has been oriented to grid connected application. Results show good chances for this power target plants to diffusion in next decades.

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    Keywords: Organic Rankine Cycle, Concentrated Solar Power, Grid Connection.


    An Intelligent Maximum Power Point Tracker for Photovoltaic Systems based on Neural Network

    by Mohamed Mostefai, Abdallah Miloudi ,Yahia Miloud


    Abstract - To maximize a photovoltaic (PV) system's output power, continuously tracking the maximum power point (MPP) of the system is necessary. The MPP depends on irradiance conditions, the panel's temperature, and the load connected. In this paper, an intelligent system for attaining maximum power point tracking of PV systems is proposed. In this method, two outputs of neural network are used to provide the optimum voltage and monitor the state of health of the photovoltaic installation at the same time. If there's a difference between the calculated power and the maximum power point, the second output of the neural network is set to 1 and an alarm is triggered. The method is tested in a 1.2kw PV system under several conditions (normal operating and default). Finally, the results of simulation are included and explained to validate the proposed techniques.

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    Keywords: Photovoltaic, Neural Network, MPPT, Fault Detection.


    New Passive Islanding Detection Method based on Cumulative Sum of Change in Voltage Positive Sequence Phase Angle

    by H. Laaksonen


    Abstract - A large non-detection zone near a power balance situation and unwanted distributed generation tripping due to other network events have been the major drawbacks of traditional, passive local islanding detection methods. Usually these traditional methods have also been dependent on the type of the distributed generation unit. In this paper new improved passive, local islanding detection method based on cumulative sum (CS) of change or rate-of-change in voltage positive sequence phase angle is proposed for distributed generation (DG) units and example simulation results are presented. The usage of CS for islanding detection is beneficial because it enables faster islanding detection especially when power unbalance is small and the variable used for islanding detection oscillates after islanding. In addition, the proposed new islanding detection method is not dependent from DG unit type, has smaller non-detection zone (NDZ) and is less susceptible to nuisance tripping as well as can detect islanding faster than the traditional passive islanding detection methods.

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    Keywords: Distributed Generation, Islanding Detection, Loss-of-Mains Protection, Anti-Islanding, Islanding, Smart Grids.


    Use of Wavelet Transforms for the Minimization of Harmonics using Shunt Active Power Filter

    by Priyadharshini A., Devarajan N.


    Abstract - In the modern world, the use of non linear loads have increased due to the industrial revolution. They generate distortions in supply voltage and current waveforms. These distortions in the voltage and current waveform specified as harmonics reduce the quality of the power that is supplied. Hence harmonic reduction becomes a necessary issue and the use of Shunt Active Power Filter (SAPF) for minimizing the harmonic content caused by the non linear load has been discussed in this paper. Here, the wavelet transform based method is used and it provides an alternative for the harmonic analysis. With this method, distortions due to different sub-band harmonics can be easily estimated and each harmonic component can be evaluated. A comparison between the Fast Fourier Transform (FFT) method and wavelet based method in determining the Total Harmonic Distortion (THD) is made. The results depict the effectiveness of the proposed method.

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    Keywords: Harmonics, Shunt Active Power Filter, THD, Wavelet Transforms.


    Multi-Area Unit Commitment Using Particle Swarm Optimization Approach

    by S. Chitra Selvi, M. Balasingh Moses, C. Christober Asir Rajan


    Abstract - This paper presents a novel approach to solve the Multi-Area unit commitment problem using particle swarm optimization algorithm. The objective of the multi-area unit commitment problem is to determine the optimal or a near optimal commitment strategy for generating units located in multiple areas that are interconnected via tie –lines. This strategy of multi-area joint operation of generation resources can result in significant operational cost savings. The dynamic programming method is applied to solve Multi- Area Unit Commitment problem and particle swarm optimization algorithm which is embedded for assigning optimum generation. The optimum allocation of generation is assigned to each area and the power is allocated to all committed units. The tie-line transfer limitations are considered as a set of constraints during the optimization process to ensure the system security and reliability. IEEE test systems are used as numerical examples to test the proposed algorithm. The feasibility of the new algorithm is demonstrated by the numerical example, and particle swarm optimization solution methodology is efficient than other algorithms.

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    Keywords: Multi-Area Unit Commitment, Evolutionary Programming, Particle Swarm Optimization, Dynamic Programming.


    Reactive Power Dispatch and its Pricing in Re-Structured Electricity Markets Using Voltage Stability Margin

    by V. Mahesh, N. Kamaraj, J. R. Deepeeha


    Abstract - This paper proposes a novel method of reactive power management and pricing in the background of re-structured electricity market. Financial compensation for reactive power support provided by the generators is considered in this paper along with the consideration of voltage stability margin. Those generators which have re-scheduled its real power generation to provide more reactive power are eligible for payment. The system operator has to find the optimum re-scheduling and minimum payment using RGA and PSO. This procedure is illustrated using 6 bus system and IEEE 30 bus system. The results show that cost of reactive power is optimum for PSO when compared with RGA for the given conditions.

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    Keywords: Capability Curve, Genetic Algorithm, ISO, Re-Schedule, Loss of Opportunity Cost.


    Wavelet Based Spike Propagation Neural Network (WSPNN) for Wind Power Forecasting

    by Smitha Elsa Peter, Santosh Kulkarni, I. Jacob Raglend, Sishaj P. Simon


    Abstract - The development of wind power generation in many countries around the world in recent years has drawn the attention of research scientists to forecast wind power. The characteristics of the wind power generated are extremely variable, non-periodic and unpredictable. Therefore, wind power forecasts have gained a lot of prominence and its significance in turbine control, pre-load sharing and trading of power. Based on the literature survey, though various wind power forecasting models have been proposed, scope for developing much more efficient and accurate models is still a major challenge. This work proposes a wavelet based spike propagation neural network for wind power forecasting. First the preprocessing of historical data is carried out using wavelet technique. Then, the third generation artificial neural networks, that involve the spike response neuron model (SRNM) is trained using the gradient descent approach. The proposed model is tested on the historical wind power data obtained from Irish power grid and National Renewable Energy Laboratory (USA) website. The performance of the proposed model is validated based on the indices such as modified mean absolute percentage error (MMAPE), root mean square error (RMSE) and error variance.

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    Keywords: Artificial Neural Networks, Spike Response Model (SRM), Spiking Neurons, Wind power forecasting (WPF).


    Review on Developments in Wind Energy Generation and its Integration to Utility Grid

    by Sony Kurian, Sindhu T. K., Elizabeth P Cheriyan


    Abstract - Efficient conversion of wind power to electricity and its integration to the grid has been a topic of intense research in recent times, to improve the contribution of energy from renewable sources. When the penetration level of wind generation increases in grid, dynamic and transient behaviour of the system get affected. To maintain the reliability of the system, well defined grid codes are to be formed that has to be followed by independent power producers to avoid wind energy curtailment and ensure quality of power available in grid. Given the intermittent nature of wind, the subject of various storage mechanisms becomes critical to avail energy scheduling from a wind farm. This paper undertakes an exhaustive study of various wind electric generators and grid integration technologies along with the grid codes. The review highlights that direct driven generators dominate in recent installations due to their superior performance compared with other generator configurations. Consequently, a permanent magnet synchronous generator based gearless wind electric system along with battery energy storage is modeled and its performance is evaluated. The grid codes that are to be followed are also incorporated in the model.

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    Keywords: Wind Energy, Integrated Operation, Grid Codes, Fault Ride Through.


    Voltage and Frequency Control of Wind Driven Stand-Alone Self-Excited Induction Generator using DCMLC based STATCOM

    by T. Elango, A. SenthilKumar


    Abstract - This paper describe the methods employed to control voltage and frequency of a 3-Ø stand-alone self-excited induction generator (SEIG) driven by a variable speed wind turbine. An attempt made to control the terminal voltage of SEIG by using a 3-Ø diode clamped multilevel converter (DCMLC) based STATCOM operation. A 3-Ø diode bridge rectifier with a d.c chopper circuit is employed to control the frequency of generated voltage. The VAr required by the load and the machine owing to changes in magnetizing reactance’s are compensated by DCMLC–STATCOM operate with full load excitation capacitance. To emphasis the controller characteristics, mathematical model of the controller is developed and implemented in MATLAB / SIMULINK software.

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    Keywords: Self-Excited Induction Generator, Voltage and Frequency Control, DCMLC-STATCOM.


    Optimal Allocation of Multi-Type FACTS Devices for Security and System Loadability Enhancement

    by Kamel Tlijani, Tawfik Guesmi, Hsan Hadj Abdallah


    Abstract - The Flexible AC transmission System (FACTS) devices, such as, thyristor controlled series compensators (TCSC) and Static Var Compensator (SVC) can be used to enhance power system performance. To achieve a better use of FACTS devices and because of their considerable costs, it is important to limit the number of theses controllers and locate them optimally in the power system. Firstly, we have applied optimization technique, namely, NSGA-II, to find out the optimal number of multi-devices of TCSC and SVC in order to improve the system loadabilty and to ensure the steady state security of the network. Secondly, we performed a contingency analysis procedure based on severity index (SIL) to identify and classify the most severe line contingencies. Then, we determined the optimal placement and parameter setting of FACTS devices in power system by using the above optimization approach to alleviate the line overloads. To ensure the robustness and effectiveness of the proposed method, N−1 contingency analysis and the stress of power system are considered. The optimization problem presented in this paper aims at reducing FACTS installation cost and decreasing total real power losses. Simulations are performed on IEEE 30-bus test system.

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    Keywords: FACTS Location, Severity Index, Power Systems, System Loadability.


    Application of S-Transform for Fault Detection during Power Swing

    by Nor Zulaily Mohamad, Ahmad Farid Abidin, Ismail Musirin


    Abstract - Distance relay is designed to block the tripping operation during a power swing. However, if a fault occurs during a power swing, it should be detected and unblocking function should be evoked to clear the fault as soon as possible. Fault detection during a power swing poses a challenging task. This paper presents an intelligent approach to detect fault during a power swing for correct distance relay operation based on S-Transform analysis on the active power at distance relay point. It is demonstrated that the proposed scheme is very fast and able to accurately discriminate the fault from power swing. To ascertain validity of the proposed scheme, simulations are carried out with the IEEE 9 and 14 bus test systems and its performance have been compared with the wavelet transform based power swing unblocking scheme.

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    Keywords: Distance Protection, Power Swing, S-Transform, Symmetrical Fault, Unsymmetrical Fault.


    Transient Stability Enhancement of a Power System using Unified Power Flow Controller

    by Poonam Singhal, S. K. Agarwal, Narender Kumar, Anirudh Dube


    Abstract - In this paper an attempt has been made to investigate the transient stability enhancement of SMIB system using UPFC controller. UPFC modeling has been done by measuring the parameters locally at the bus. The proposed controller is found to be suitable for operating in both voltage regulation and PQ mode. To mitigate the power oscillations in the system, the required amount of series voltage injected by UPFC controller has also been computed. It is also found that the proposed controller works effectively under low as well as high range of power rating of generator.

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    Keywords: UPFC, Transient Stability, Converters,SMIB, Synchronous Machine Modeling, Capacitor Dynamics.


    Modeling of Control and Power Management of a Hybrid Wind-Solar System Using Optimization Technique

    by L. Sabari Nathan, L. Ashok Kumar, B. Vaikundaselvan, S. Ravi Krishna


    Abstract - A probabilistic methodology is described in this paper to determine an optimal design and implementation of a multi source hybrid like Wind, Photovoltaic (PV) stand alone system with energy management strategy. Hybrid energy system is an excellent solution for electrification of remote rural areas where the grid extension is difficult and not economical. Hybrid (Wind-PV) system are highly efficient and requires very low maintenance. An average model of a hybrid Wind-PV generating system is presented. The Model is important for synthesizing the control strategy and analyzing the dynamic behavior of the system. The main objective is to provide 24 hours demand quality power in remote communities. The method of investigation concerns with the definition of the system topology, interconnection of the various sources with maximum energy transfer, optimum control and energy management. The proposed energy management strategy is simulated for Very Low Voltage (VLV) node connection and its coupled with DC loads in MATLAB/Simulink using the Fuzzy Logic Controller (FLC). The FLC takes the input from Solar (irradiation), Wind (speed) and the battery and controls the respective subsystem which formulates into different operational modes of energy management. The role of Fuzzy threshold controller is to adjust continuously the threshold value for optimal performance based on expected wind, solar conditions and batter voltage. It is shown that, when the Fuzzy Logic Controller is used.The proposed Direct Current (DC) bus voltage regulation strategy with different modes of operation has fast response and efficient operation which leads to a reduced operating cost. The optimal power transfer from the source to load is based on mechanism which are used to control power, voltage and current and these parameters are used to regulate the DC bus voltage to a fixed value. The various models with the output waveforms are represented and discussed. Finally, simulation results are presented to verify the effectiveness and accuracy of the proposed system.

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    Keywords: Control and Energy Management System, Fuzzy Logic Controller, Hybrid Wind-Solar System, Photovoltaic Conversion, Power Modeling, Wind Conversion System.


    Independent Power Producer Locality Effect on Wheeling Cost

    by I. Kranthi Kiran, A. Jaya Laxmi


    Abstract - The need for more efficient generation and provision of electric power has led the setting of electric power industry to change quickly from its regulated conventional setup to a deregulated one, in several countries, traditionally under the control of federal and state governments. One of the important aspects of the policies liberalized by the Indian government in 1990s is the opening of power generation to private sector that has resulted in the entry of Independent Power Producers (IPPs) into power generation field. IPPs make use of third-party owned transmission network to “wheel” the electrical energy to its customers. The wheeling party is paid ‘Wheeling cost’ annually for its service as well as for meeting the losses. This paper introduces the concept of wheeling, summarizes different types of embedded wheeling cost methodologies and gives a detailed presentation of an ‘embedded’ wheeling cost methodology namely ‘MVA-km’ method to determine the annual wheeling cost. The wheeling cost is calculated by the MVA-km method and compared by changing the location of seller, to an application example illustrated.

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    Keywords: Wheeling, Transmission Transaction, Independent Power Producers, Embedded Cost, Wheeling Cost.


    Sensitive Area Clustering based on Voltage Stability and Contingency Analyses with Impact of Line Stability Indices

    by M. Jagadeeshkumar, Subhransu Sekhar Dash, Subramani Chinnamuthu


    Abstract - With a growing concern for maintaining stable voltage operation within the network, many critical issues on voltage stability related studies have been raised in the area of power system research. The problem of voltage stability is one of the main concerns in the operation of power systems. Due to the excessive load demand and non-linearity in loads leads to voltage instability and ultimately leading to voltage collapse. Voltage collapse has to be given the utmost priority because it led to cascading blackouts in the whole network. A voltage stability index is that which examines the voltage stability condition formulated based on line in a power system and identifies sensitive bus of the system to maintain the stable system, which will be great importance. With the help of Voltage stability index, the point of voltage collapse, critical line and critical voltage with respect to load bus are identified. Also this paper deals the development of the sensitive area clustering technique based on the results obtained from voltage stability analysis and contingency analysis. The performance of this index is presented and the effectiveness of the analyzed methods is demonstrated through simulation studies in IEEE 30 bus test systems.

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    Keywords: Contingency Analysis, Contingency Ranking, Voltage Stability, Voltage Stability Index, Sensitive Area Clusters.


    An Application of Differential Search Algorithm in Solving Non-Convex Economic Dispatch Problems with Valve-Point Effects

    by Mohd Herwan Sulaiman


    Abstract - This paper presents an application of Differential Search (DS) algorithm for solving non-convex economic dispatch (ED) problems with the valve loading effects. ED is one of the most challenging problems of power system since it is difficult to determine the optimum generation scheduling to meet the particular load demand with the minimum fuel costs while all constraints are satisfied. In addition, the practical ED problems which are involving non-convex objective functions with equality and inequality constraints including the practical operation constraints of generators such as ramp rate limit, prohibited operating zones and generation limits make it harder to solve the global optimum using conventional methods. In this paper, DS is adopted to find the global optimum results of ED. To demonstrate the effectiveness and feasibility of DS in solving ED, four well known ED test systems with non-convex solution features have been tested and compared with some of the most recently published ED solution methods in literature. The results of this research show that DS is able to find more economical solution than those determined by other methods.

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    Keywords: Differential Search Algorithm, Economic Dispatch, Swarm Intelligence, Valve-Point Effects.


     Part A - Part B

    On the Suitability of DEKF for Improving GPS Location in Car Accidents

    by L. Angrisani, A. Liccardo, N. Pasquino, R. Schiano Lo Moriello P. Bifulco, M. Laracca, A. M. Lanzolla


    Abstract - The first fundamental step within a research project aiming at the 3D reconstruction and rendering of the accident scenes involving motor vehicles is accounted for. More specifically, the paper deals with the problem of accurately locating and georeferencing both the considered scenario and all involved elements (such as cars, debris, peeling out and so on) of interest for Road Safety experts. A new method, based on Kalman filtering, is presented for enhancing the preliminary estimates, obtained through low-cost GPS devices, of the position of proper scene markers. To this aim, the distances between the markers is measured through a low-accuracy device (as an example, an ultrawideband radar) and the achieved results are used as feedback to improve the estimate of markers positions. Preliminary results, obtained in numerical tests, are presented to prove the feasibility of the method, thus suggesting its implementation in an actual measurement station.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Locating and Georeferencing Data, Cars Accident, GPS Devices, Discrete Extended Kalman Filter.


    Modeling and Analysis of Magnetic Resonance Coupled Wireless Power Transfer Systems

    by Zhigang Dang, Jaber A. Abu Qahouq


    Abstract - Magnetic resonance coupling (MRC) is a practical high efficient method for midrange wireless power transfer (WPT). In a MRC-WPT system, when the gap between transmitter (Tx) and receiver (Rx) is shorter than the critical coupling distance, the strong coupling will result in two natural resonance frequencies (frequency splitting). When increasing the gap between Tx and Rx, the coupling becomes weaker, and the split resonance frequencies become closer to each other and eventually merge into a single natural resonance frequency. As long as frequency splitting exists, a near to constant maximum power transmission efficiency can be maintained. In this paper, commonly used four-loop and two-loop WPT system configurations are analyzed and compared based on the simplified circuit model. An example symmetrical system simulation shows that with the same Tx, Rx, source and load, the four-loop system has longer transmission distance with relatively lower efficiency compare to the two-loop system. A 3-D physical model of 5-turn, 400mm outer diameter spiral shape four-loop WPT system is designed and simulated by using ANSYS® HFSS®. Operation distance of 550mm with nearly constant maximum transmission efficiency of 92.3% is achieved.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Wireless Power Transfer, Four-Loop, Two-Loop, Magnetic Resonance Coupling, Frequency Splitting, Critical Coupling, Maximum Transmission Efficiency, Effective Inductance, Circuit Model, Physical Model.


    Analysis of Multilayer Planar Circuits by Hybrid Method

    by R. Gharbi, H. Trabelsi, A. Gharsallah, H. Baudrand


    Abstract - The paper discussed the implementation of the hybrid algorithm to modelling the multilayer planar circuit by combine the FDFD method and WCIP method. The finite difference frequency domain (FDFD) algorithm can be used to modelling the 3D discontinuity structure, with the open region modelled by iterative method. The well agreement between our method and original FDFD method demonstrated the validity and flexibility of the method. Memory requirement is greatly reduced by using DDM.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Hybrid Numerical Method, FDFD Method, Hybrid WCIP Method.


    Analysis of Electromagnetic Wave Propagation along Optical Waveguide

    by M. Bacha, , A. Belghoraf


    Abstract - The Analytical method elaborated in this paper is based on a concept of geometrical optics to analyse optical wave propagation along non-uniform optical waveguide. This model will be applied to physical structures which are used in integrated optics to analyse the electromagnetic field distribution inside the guide. To analyse the field distribution inside the non-uniform waveguide and predict the beam propagation of optical energy involved in the propagation process, it is necessary to track the motion of rays of the spectrum undergo bottom and top reflections on boundaries, when total internal reflections prevail. The model introduced allows us to determine the distribution of the electromagnetic field inside the waveguide in the region of guided waves. Good agreement is found between the model described hereby and others similar mathematics model, the results performed show also agreement with conventional methods of evaluation used by other works.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Electromagnetic Wave, Integrated Optics, Numerical Method, Optical Waveguide, Geometrical Optics.


    Using Simulation in Virtual Reality Environment to Find Effects of Human Operators on the Life-Cycle Efficiency of Off-Highway Working Vehicles

    by Lauri O. Luostarinen, Heikki Handroos


    Abstract - Virtual Reality (VR) environments and real-time simulators are becoming more and more important tools in R&D process of off-highway working vehicles. The virtual prototyping techniques enable faster and more cost-efficient development of machines compared to use of real life prototypes. Possibilities of virtual prototypes should be studied to take full advantage of them. The objective of this article is to study the process of using a VR environment with a real-time simulator for assessing effects of human operators on the life-cycle efficiency of working vehicles. As a test case human in the loop simulations are ran by virtual prototype of Load Haul Dump (LHD) underground mining vehicle. Results of test drivers are compared and discussed. The simulation model of the LHD is based on multibody dynamics. The model also includes models of diesel engine, mechanical driveline and fluid power system. The study shows that state of the art real-time working machine simulators are capable to solve factors related to life-cycle efficiency such as energy consumption and productivity among others. A significant variation between the test drivers is found. The study shows that VR environment can be used for assessing human effects on the life-cycle efficiency of working vehicles.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Construction Machinery, Efficiency, Energy, Human, Simulation, Virtual Reality, Working Vehicle.


    An Algorithm for Setting the Dynamic Parameters of the Classic Distribution Mechanism

    by Florian Ion T. Petrescu, Relly Victoria V. Petrescu


    Abstract - This paper presents an algorithm for setting the dynamic parameters of the classic distribution mechanism used in the internal combustion engines. New requirements of distribution mechanisms are that they can work at very high speeds without vibration or noise. Because of this, the settings of the valve spring must be pre-calculated rigorously. One sets the spring elastic constant k, and the spring pretension x0. The algorithm used is written in Excel.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Spring Elastic Constant, Spring Pretension, Algorithm, Excel.


    Design and Comparative Analysis of Mathematical and Simulation Models in Injection Molding Decision System

    by V. Seralathan, C. Jegadheesan


    Abstract - Injection molding is a very challenging process for many manufacturers and researchers to produce the products meeting requirements at lower cost. Many algorithms and techniques have been developed with simulation and mathematical models for the injection molding design and development process. Some mathematical or simulation techniques improve the production capacity, while some other improve the quality of knowledge base. But, it is uncertain that all these mathematical or simulation model based techniques provide high production capacity at all times. Thus, analysis is necessary for the techniques that are utilized in the injection molding process. Hence, in this study, a mathematical model for the injection molding decision system is proposed. The injection molding decision system with efficient parameters is developed by means of both simulation and mathematical models. In both models, the product quality value is computed by utilizing parameter values in different experiments and the decision is taken by using the environment parameters and the computed quality values. The performance of both analytical models in the injection molding decision system is analyzed with more experimental parameter values. Moreover, the performances of both models are compared to find the model having high score performance in product quality as well as in molding decision.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Injection Molding Design, Feed Forward Back Propagation Neural Network (FFBNN), Fuzzy Inference System (FIS), Fuzzy Rules, Process Parameters, Simulation Based Model, Mathematical Based Model and Polynomial Coefficients.


    Improvement of Element Creation Procedure for Generating Initial Triangular Unstructured Mesh for Radiative Heat Transfer Modelling

    by Abas Z. A., S. Salleh, Rahman A. F. N. A., Basiron H., Hasan Basari A.S., Hassim N.


    Abstract - In this paper, the methods for generating triangular unstructured mesh that follow the approach of Advancing Front Techniques (AFT) are studied. Extended Advancing Front Technique (XAFT) is also another technique that is usually used to generate triangular unstructured meshes especially in radiative heat transfer modeling. The proposed technique which called The Seven Cases Unstructured Triangulation Technique (7CUTT) is compared with the Extended Advancing Front Technique (XAFT). This paper highlights the differences resulted from the transformations with regards to its radius and the cases of consideration during element creation procedure for both techniques. The unstructured mesh generated from both techniques is then integrated with the governing equation of radiative heat transfer in order to obtain the approximation of flue gas temperature in the simplified conceptual model of ethylene furnace by using Discrete Ordinate Method (DOM) in FLUENT software. From the results, the quality of the generated mesh in the simulation using both techniques is compared.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Extended Advancing Front Technique, Seven Cases Unstructured Triangulation Technique, Radiative Heat Transfer, Triangular Unstructured Mesh.


    A Stabilization Approach of a CSTR with Two Arbitrarily Switching Modes Using a Common Control Lyapunov Function

    by Abdessamad Abdelhedi, Lasaad Sbita


    Abstract - This paper presents a study of stabilization for a class of the nonlinear switched systems. This study, indeed, is based on stabilization by using control Lyapunov functions. Firstly, a necessary and sufficient condition of stabilization is clarified. This condition hinges on the existence of a common control Lyapunov functions in the switching subsystems. The common controlled Lyapunov function is explicitly built by using controlled Lyapunov functions associated with the sub-systems. Secondly, a stabilization controller is designed for the nonlinear switching system by using the common Lyapunov function theory. Lastly, to illustrate this study, the example of a continuous stirred tank reactor (CSTR) with two modes is deemed to show the applicability of the suggested approach.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Switched Systems, Stabilization, Control Lyapunov Functions, CSTR.


    Prediction of Wear Behavior of Epoxy-MWCNTS Nanocomposites Using Artificial Neural Networks

    by C. Sabarinathan, S. Muthu, R. Arunkumar


    Abstract - The potential of using Artificial Neural Networks (ANN) for predicting the dry sliding wear behavior of Multiwall Carbon Nanotubes (MWCNTs) reinforced epoxy material was investigated in this work. The effects of reinforcement content 0.1%, 0.5%, 1.25%, 2.5% and 5% weight fraction of MWCNTs nanocomposites wear properties were determined by the pin on disc machine. A polymer nanocomposite was investigated using a measured datasets of 80 independent dry sliding tests of pure epoxy and epoxy-MWCNTs. It was tested under various testing conditions of applied loads of 30N and 60N, sliding speed and time is 200rpm and 30min respectively. Based on measured datasets of epoxy-MWCNTs nanocomposites, specific wear rate was successfully calculated through well trained artificial neural network. Feed forward back propagation neural network (FFBN), radial basis neural network (RBNN), pattern recognition neural network (PRNN) and general regression neural network (GRNN) algorithm models were investigated in order to predict the optimum method that simulates the wear under such parameters. The experimental results were trained in an ANN and the results were compared with experimental values. The GRNN network demonstrated that the average value of relative error is <1% and prediction quality 99% and it is quite suitable tool for prediction of wear in composites.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Artificial Neural Network, Epoxy, Multiwall Carbon Nanotubes, Polymer Nanocomposites, Wear.


    The Formation of Action Strategies in Active Hierarchical Systems

    by Rekik Ali, Moncef Temanni, Mounir Gabsi


    Abstract - Over the last decade much research effort has been focused on the investigation of goal-oriented techniques to capture and represent the requirements of a system from an intentional point of view. Large distributed real-time embedded systems are often designed with static resource management strategies tailored for specific goals or missions. These rigid resource allocation strategies are incapable of adapting to changing system goals, resource levels and operating environments. Intelligent agents offer one approach to operationalizing a decision making support system in these circumstances by providing an environment that can adapt to speed and change. Designing large-scale and hierarchical systems often involves making selections from multitudes of alternative decisions, strategies and configurations. In this paper we propose a models of strategies actions which are realized by intellectual agents in the cognitive systems to ACS-TP.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Agent, Goal-Seeking, Logic, Cognitive Model, Intellect and Strategy.


    Architecture for Data Coordination Processing and Real time Services in Smart Grid Environment

    by Rajeev T., Ashok S.


    Abstract - Smart grid is a complex network, consisting of large number of energy sources, controlling devices and load centers. The time varying characteristics of these grid elements demands a dynamic smart grid management platform for offering various services. The cloud environment provides a flexible way of building and facilitating computing and storage infrastructures for various online and offline services. In this paper, an architecture is presented for coordination and processing of linked data in smart grid environment. Priority strategy is considered for application level performance management in the framework. The architecture offers data storage and management with minimum hardware. Also it supports different spatial and temporal requirements for operation services. The case is simulated to evaluate the suitability of cloud architecture for real time services. The simulation experiment has been conducted in the Cloud test bed. Analytical model based on queuing theory has been developed for performance evaluation. The test results show that, the architecture can effectively handle the data coordination and processing in smart grid environment to offer various online services. The priority strategy provides significant improvement in the performance result.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Mean Response Time, Openstack, Smart Grid, Scheduler, Virtual Machine.


    A Comparison Study between Two Algorithms Particle Swarm Optimization for Depth Control of Underwater Remotely Operated Vehicle

    by M. S. M. Aras, S. S. Abdullah, H. I. Jaafar, Razilah A. R., Arfah Ahmad


    Abstract - This paper investigates two algorithms based on particle swarm optimization (PSO) to obtain optimum parameter. In this research, an improved PSO algorithm using a priority-based fitness PSO (PFPSO) and priority-based fitness binary PSO (PFBPSO) approach. This comparison study between two algorithms applied on underwater Remotely Operated Vehicle for depth control. Two parameters in Single Input Fuzzy Logic Controller will tune using two algorithms to obtain optimum parameter. There are two parameters to be tuned namely the break point and slope for the piecewise linear or slope for the linear approximation. The study also covered a comparison for time execution for every time the parameter tuning was done. Based on the results the PFBPSO gives a consistent value of optimum parameter and time execution very fast. The best optimum parameter of SIFLC determined using 2 methods such that average of optimum parameter and intersection of y-axis. The PFBPSO gives comparative results in term of two parameters and time execution very fast compared with improved PSO.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Priority Fitness PSO, Priority Fitness Binary PSO, Optimum Parameter, Single Input FLC, Time Execution.


    Banking Operations and Strategic Marketing Plans: a Causal Loop Based Model for Finance Sector

    by P. Centobelli, G. Converso, T. Murino, L. C. Santillo


    Abstract - The following paper is focused on the operating conditions for the implementation of tertiary sector marketing planning. This issue, related to the instruments and techniques from which it stems, constitutes the essential tool to compete in western markets of services. The suggested approach is oriented to design a technical model determined by conditions set selected. We used four groups of performance indicators, able to define the business strategic position of company. Afterwards using the system dynamics criteria we suggest a CLD graph which represents the interactions among the several factors that influence the company behavior related to its strategy evolution. The model is characterized for the financial market, so that the performance indicator are assessed for a bank. In the case of study we analyze a specific Bank operating in southern of Italy and we define the new marketing strategy starting from its current state and market objects through the proposed model.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Strategic Analysis, Intelligent Business, Causal Loop Diagram, Marketing Planning.


    Inclusion of Complexity: Modelling Enterprise Business Environment by Means of Agent Based Simulation

    by Petr Tučník, Vladimír Bureš


    Abstract - Description of enterprise environment can be modelled by various approaches that emphasise diverse perspectives. The application of multi-agent models is currently used for their advantages such as system’s emergence identification or complexity depiction. The aim of this paper is to apply multi-agent approach to modelling of a complex economic system using four basic types of agents and one meta-agent. Consequently, the model is simulated, different settings are tested, and coordination and self-organization are investigated. Although the proposed system is in several aspects simplified in comparison to reality, it provides useful basis for research of adaptation mechanisms, manufacturing management, supply chain management, or customer behaviour modelling. Experiment results show that individual goals and strategies are forming collective effort of pursue of given goals, respecting constraints and limitations set on level of the whole agent community.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Agent, Modelling, Simulation, Virtual Economy, Self-Organization, Adaptation.



    Extracted by "4th ICOMOS 2013 - Virtual Forum"


    Efficient Methods Used to Create Hydrogeological Model of Latvia

    by A. Spalvins, J. Slangens, I. Lace, O. Aleksans, K. Krauklis


    Abstract - In 2010-2012, the hydrogeological model (HM) of Latvia LAMO was established by scientists of Riga Technical University. The commercial program Groundwater Vistas (GV) is used for running LAMO. GV includes the worldwide applied MODFLOW program. Efficient methods were used for creating geometry of HM, for arrangement of various boundary conditions (digital terrain map, hydrographical network, infiltration flow, conditions on the HM shell surface) and to calibrate HM. Their appliance considerably improved quality of HM and reduced time needed to create LAMO.

    Copyright © 2013 Praise Worthy Prize - All rights reserved


    Keywords: Regional Hydrogeological Model, Boundary Conditions, Finite Difference Approximation.


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