WSEAS Transactions on
Power Systems

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Print ISSN: 1790-5060
E-ISSN: 2224-350X

Volume 8, 2013

Issue 1, Volume 8, January 2013

Title of the Paper: Analysis and Simulation of Single-Phase and Two-Phase Axial Flux Brushless Dc Motor

Authors: Reaza Ashrafi Habibabadi, Amir Nekoubin

Abstract: The objective of the paper is to analyze and compare the performances of the axial flux permanent magnet brushless dc (AFPM BLDC)motor with single-phase winding and two-phase winding. To study the motor operation, a mathematical dynamic model has been proposed for each of the motor with different winding, which became the basis for simulations that were performed using MATLAB/SIMULINK software package. The calculation results show that the two-phase motor version develops more smooth torque and reaches higher efficiency than the single-phase version. However the advantage of using a single-phase version is simpler and cheaper converter which the motor is supplied from. This implicates of using this type of motor for fans and pumps where torque ripple is not the subject, while the two-phase motor can be applied where more smooth torque is required. Both motors are supplied from inverter whose structure depends on the type of winding. Since there were voltage type inverters, the switching angle of transistors had significance on the motor performance. This influence was studied for both motors.

Keywords: Brushless DC motor, Switching angle, Inverter, and Dynamic

Title of the Paper: Design of PID Controller for Power System Stabilization Using Hybrid Particle Swarm-Bacteria Foraging Optimization

Authors: H. I. Abdul-Ghaffar, E. A. Ebrahim, M. Azzam

Abstract: This paper considers the stabilization of a synchronous machine connected to an infinite bus via a PID. The PID parameters are tuned using hybrid Particle Swarm-Bacteria Foraging Optimization (PSO-BFA). Simulation results are introduced with and without the proposed controller. Also, a comparison study is introduced when using classical PID, only bacteria foraging optimization and when using hybrid particle swarm- bacteria foraging optimization. The results show that using of hybrid control is capable of guaranteeing the stability and performance of the power system better than the PID-PSS based classical PID and BFA only.

Keywords: Bacteria Foraging Algorithm, Particle Swarm Optimization , PID Controller, PSS, Chemotaxis, Mutation, Objective function

Title of the Paper: Wind Power Plant Data Monitoring and Evaluating

Authors: Arben Gjukaj, Rajmonda Bualoti, Marialis Celo, Miranda Kullolli

Abstract: Smart grid technologies possess great potential to modify costumer performance with respect to energy consumption, in both automatically and non-automatically This paper provides a statistical analysis of the performance of a wind power plant through monitoring the obtained data, evaluating the system performance and predicting possible measures that can be undertaken. The monitoring equipment was placed at key locations throughout the wind plant, most specifically at the points of connection with the transmission system. Real and reactive powers, along with three-phase voltages at the interconnection point, were sampled and stored. Results have been valuable to evaluate the probability of wind power variations, capacity factors, as well as to analyze ancillary service requirements with real wind power plant output.

Keywords: Wind power plant, Power System, Monitoring, Statistics, Smart grid, Ancillary service

Title of the Paper: Effects of Environmental Factors in Transformer’s Insulation Life

Authors: M. Srinivasan, A. Krishnan

Abstract: The Hot Spot Temperature (HST) value depends on the ambient temperature, the rise in the top oil temperature (TOT) over the ambient temperature, and the rise in the winding HST over the top oil temperature. In this paper a new semi-physical model comprising of the environmental variables for the estimation of HST in transformer is proposed and also MATLAB/Simulink-based valid model of hot spot temperature under variable environmental condition is proposed. The winding hot-spot temperature can be calculated as a function of the top-oil temperature that can be estimated using the transformer loading data, top oil temperature lagged regressor value, ambient temperature, wind velocity and solar heat radiation effect. The estimated HST is compared with measured data of a power transformer in operation. The proposed model has been validated using real data gathered from a 100 MVA power transformer

Keywords: Top Oil Temperature - Hot Spot Temperature – Environmental variables

Title of the Paper: Realization and Characterization of an Electronic Instrument Transducer for MV Networks with Fiber Optic Insulation

Authors: Daniele Gallo, Carmine Landi, Mario Luiso, Edoardo Fiorucci

Abstract: As a consequence of increasing interest in power quality analysis, the measuring instruments used in electrical power systems are now charged with new tasks to be undertaken for which the equipment already installed or traditionally used are very unlikely to be adequate. Particular problems come from the first part of each electrical measurement chain: voltage and current transducer are profitably usable only in a narrow 50-400 Hz frequency range while for power quality analysis a much larger frequency range should be analyzable. This paper presents a voltage transducer prototype designed to be installed in medium voltage systems. The presented design criteria try to face both the bandwidth limitations and the accuracy problems that characterize commercial transducers commonly adopted. In addition, the presented implementation keeps the galvanic insulation characteristic, that is mandatory for this kind of equipment. Commercial components are used in the presented prototype to keep the budgetary requirement low. Some results of prototype characterization are presented in the last part of the paper.

Keywords: Voltage transducer, voltage measurement, medium voltage, power quality

Issue 2, Volume 8, April 2013

Title of the Paper: Design and Implementation for Wide Area Power System Monitoring and Protection Using Phasor Measuring Units

Authors: Waheed Ur Rahman, Muhammad Ali, Chaudhry A. Mehmood, Asadullah Khan

Abstract: The increasing demand of load without considerable increase in transmission resources has posed numerous constraints and challenges in the power system monitoring and performance. The inadequacy in transmission resources has resulted in reduced operational margins for many power systems worldwide and has led to operation of power systems closer to their stability limits and to power exchange in new patterns. The issues of deregulation trend in the industry and the requirement of better network monitoring, leads to the development of the solutions for wide area monitoring, protection and control, than the currently used methods which are mostly good for local area monitoring, protection and control. The author set the time-synchronization constraints in monitoring, protection and control of remote node for wide areas to obtain data and take decisions in timely manner, preventing catastrophic consequences. The all got its importance and because of the presence of currently used insufficient methods for monitoring, protection and controlling, which cannot deliver the time-synchronization requirement. The paper gives the PMU model and complete wide area monitoring and controlling system in MATLAB/Simulink and the results are verified through simulations.

Keywords: Wide area monitoring protection and control (WAMPAC), Phasor measurement unit (PMU), Wide area monitoring (WAM), Global positioning system (GPS)

Title of the Paper: Power System Quality Improvement Using Flexible AC Transmission Systems Based on Adaptive Neuro-Fuzzy Inference System

Authors: M. Ramadan Sayed, M. A. Moustafa Hassan, A. A. Hassan

Abstract: This paper introduces comprehensive fast control characteristics and continuous compensation means using Adaptive Neuro-Fuzzy Inference System. Flexible AC Transmission System (FACTS) devices have been investigated and adopted in power engineering area. There are so many advantages in using FACTS devices. It can increase dynamic stability, loading capability of transmission lines, improve power quality as well as system security. It can also increase utilization of lowest cost generation. This paper presents a detailed Adaptive Neuro-Fuzzy Inference System based algorithm for improving power system quality using Advanced Flexible AC Transmission Systems (AFACTS) controllers. Namely, Advanced Thyristor Controlled Series Capacitors (ATCSCs), and Advanced Static Var Compensator (ASVC) were utilized in this research. This paper focuses on the operation of the FACTS device under generator fault that may cause any other transmission lines to be overflowed. Adaptive Neuro-Fuzzy Inference System (ANFIS) is used to determine the value of capacitor connected to the AFACTS. The proposed algorithm in this paper is tested on the IEEE 30 bus system as well as IEEE 14 bus system.

Keywords: Adaptive Neuro-Fuzzy Inference System, Flexible AC Transmission System, Power Quality, Voltage Sag, Total Harmonic Distortion

Title of the Paper: Synergy of Particle Swarm Optimization and Bacterial Foraging for TCSC Damping Controller Design

Authors: S. M. Abd-Elazim, E. S. Ali

Abstract: Social foraging behaviour of Escherichia coli bacteria has recently been explored to develop a novel algorithm for optimization and control. One of the major driving forces of Bacterial Foraging Optimization Algorithm (BFOA) is the chemotactic movement of a virtual bacterium that models a trial solution of the optimization problem. However, during the process of chemotaxis, the BFOA depends on random search directions which may lead to delay in reaching the global solution. This paper comes up with a hybrid approach involving Particle Swarm Optimization (PSO) and BFOA algorithm called Bacterial Swarm Optimization (BSO) for designing Thyristor Controlled Series Capacitor (TCSC) in a multimachine power system. In BSO, the search directions of tumble behaviour for each bacterium are oriented by the individual’s best location and the global best location of PSO. The proposed hybrid algorithm has been extensively compared with BFOA and PSO. Simulations results have shown the validity of the proposed BSO in tuning TCSC compared with BFOA and PSO. Moreover, the results are presented to demonstrate the effectiveness of the proposed controller to improve the power system stability over a wide range of loading conditions.

Keywords: TCSC, Multimachine Power System, Particle Swarm Optimization, Bacterial Foraging, Hybrid Algorithm, Damping Oscillations

Title of the Paper: Optimal Power System Stabilizers Design for Multimachine Power System Using Hybrid BFOA-PSO Approach

Authors: E. S. Ali, S. M. Abd-Elazim

Abstract: A novel hybrid approach involving Particle Swarm Optimization (PSO) and Bacterial Foraging Optimization Algorithm (BFOA) called Bacterial Swarm Optimization (BSO) is illustrated for designing Power System Stabilizers (PSSs) in a multimachine power system. In BSO, the search directions of tumble behaviour for each bacterium are oriented by the individual’s best location and the global best location of PSO. The proposed hybrid algorithm has been extensively compared with the original BFOA algorithm and the PSO algorithm. Simulations results have shown the validity of the proposed BSO in tuning PSSs compared with BFOA and PSO. Moreover, the results are presented to demonstrate the effectiveness of the proposed controller to improve the power system stability over a wide range of loading conditions.

Keywords: PSSs, Multimachine Power System, Particle Swarm Optimization, Bacteria Foraging

Title of the Paper: The Study on the Construction of the Smart Grid Test Plant and the Integration of the Heterogeneous Systems

Authors: Jang Moonjong, B. N. Ha, S. W. Lee, D. Y. Seo

Abstract: In this paper, the development of the smart power grid management system (SPG) will be introduced. The purpose of the system is the integration of the separate R&D systems in the power IT project. The intelligent distribution automation system(IDAS), the substation automation system (SAS), intelligent transmission system and active telemetrics are considered at present. For this, each system is first briefly introduced, following with the introduction on the development of the smart power grid management system.

Keywords: Smart Grid, Smart Grid Test Plant, SG Test Plant, Smart Power Grid, SPG Test Plant

Issue 3, Volume 8, July 2013

Special Issue: Advanced Control of Energy Systems

Title: An Introduction to the Special Issue on Advanced Control of Energy Systems

Authors: M. Azzouzi, F. Neri


Title of the Paper: Increase Efficiency of Photovoltaic Pumping System Based BLDC Motor Using Fuzzy Logic MPPT Control

Authors: Mehdi Ouada, M. S. Meridjet, M. Saad Saoud, N. Talbi

Abstract: The aim of this paper is presentation of an approach for modeling , control and optimization of a photovoltaic pumping system which contains a PV generator , DC-DC boost converter, MPPT controller, DC-AC inverter and a BLDC motor. We use an intelligent control method for searching the maximum power point (MPP). This method uses a fuzzy logic controller applied to a drive a DC–DC converter to an optimal operating point using PV panel’s measured variables. The PWM signals are generated by the interaction of the motor speed closed-loop system and the current hysteresis. The motor reference current is compared with the motor speed feedback signal. The considered model has been implemented in Matlab /simulink environment. The results show the effectiveness of the proposed method under variation irradiation ,in order to increase the performance of the water pumping system.

Keywords: Pumping system, photovoltaic, MPPT, BLDC, Fuzzy logic, Optimization

Title of the Paper: Sizing of Step-Up Transformers for PV Plants through a Probabilistic Approach

Authors: Antonio Testa, Salvatore De Caro, Tommaso Scimone

Abstract: Step-up transformers are used to connect large PV plants to the utility network, their sizing being often accomplished only taking into account the PV plant peak power. However, a largely unpredictable power injection on the main grid is obtained if a too large rated power is selected, leading to grid instabilities. This may result in plant shutdowns, while requiring a remarkable reserve power to be provided by conventional generation systems. On the other hand, a too small transformer lead to the creation of a bottleneck, preventing an optimal exploitation of the solar energy. This situation becomes more complex if the introduction of an energy storage system is considered. In the present paper a design technique is proposed to optimally select the step-up transformer, either on conventional PV plants, either on PV plants with energy storage. It is based on the evaluation of initial and operating costs. Moreover, the effects of induced network instabilities are also considered. Taking into account full life costs optimal solutions have been detected according to the network power control capabilities for a 2 MW PV plant.

Keywords: Photovoltaic power systems, Power generation, Transformers, Energy storage, Power Plants, Systems Efficiency

Title of the Paper: Improved Incremental Conductance Method for Maximum Power Point Tracking using Cuk Converter

Authors: Merwan Saad Saoud, Hadj Ahmed Abbassi, Saleh Kermiche, Mahdi Ouada

Abstract: The Algerian government relies on a strategy focused on the development of inexhaustible resources such as solar and uses to diversify energy sources and prepare the Algeria of tomorrow: about 40% of the production of electricity for domestic consumption will be from renewable sources by 2030, Therefore it is necessary to concentrate our forces in order to reduce the application costs and to increment their performances, Their performance is evaluated and compared through theoretical analysis and digital simulation. This paper presents simulation of improved incremental conductance method for maximum power point tracking (MPPT) using DC-DC cuk converter. This improved algorithm is used to track MPPs because it performs precise control under rapidly changing Atmospheric conditions, Matlab/ Simulink were employed for simulation studies.

Keywords: Improved incremental conductance, MPPT, cuk converter, rapidly changing Atmospheric conditions, Matlab

Title of the Paper: A Hybrid Approach for Economic Power Dispatch

Authors: Mimoun Younes, Riad Lakhdar Kherfane, Fouad Khodja

Abstract: In this paper, a novel hybrid optimization algorithm, which combines a firefly algorithms and Artificial Bee Colony algorithm (FFA- ABC), is proposed for solving the economic power dispatch (EPD) problem. The hybrid algorithm is structured with two stages. The first stage uses the search by firefly algorithm (FFA) and second stage is a search with Artificial Bee Colony algorithm (ABC). The hybrid algorithm involves two level of optimization, namely global search by the ABC and local search by the FFA, which cooperates in a global process of optimization. It can provide more robust convergence. The proposed method is tested in standard IEEE 30 bus and IEEE 57 bus test systems. Numerical results illustrate the feasibility and potential of the proposed hybrid algorithm.

Keywords: Economic power dispatch (EPD), Artificial Bee colony Algorithm, Firefly algorithm, hybrid method

Issue 4, Volume 8, October 2013

Title of the Paper: Optimal Operation of Ship Electrical Power System with Energy Storage System and Photovoltaics: Analysis and Application

Authors: G. J. Tsekouras, F. D. Kanellos

Abstract: The extensive electrification of ship power systems has become a very appealing alternative for the development of more efficient and environmentally friendly ships. Renewable energy sources (RES) and energy storage systems (ESS) will have a key role in such systems as they can lead to fuel consumption reduction and increase overall ship efficiency. However, the power production from RES is stochastic and hardly predicted making necessary the combined operation with ESS. In this paper the operation of a ship power system equipped with photovoltaics (PVs) and ESS is analysed from the economic point of view and analytic formulas are obtained for system marginal cost for different case studies. The proposed method leads to simple analytic mathematical relations that could be easily exploited for the technical-economical assessment of ESS and RES integration to ship electric power systems.

Keywords: Economic dispatch, ship power system, photovoltaic panels, energy storage system, system marginal cost

Title of the Paper: Parasitic Burden on the Performance of Coupled Inductor SEPIC Based Maximum Power Point Tracking in PV Systems

Authors: Nur Mohammad, Muhammad Quamruzzaman, M. R. Alam

Abstract: This paper presents the effect of parasitic resistive burden in maximum power point tracking of photovoltaic (PV) systems using coupled inductor Single Ended Primary Inductance Converter (SEPIC). The energy storage elements incorporated in the coupled-SEPIC converter possess parasitic resistances. The particular effects of parasitics have been taken into concern for improving model accuracy, stability as well as the dynamic performance of the converter in MPPT applications. Detail model of coupled-SEPIC including inductive parasitic were developed. The performance of the converter in tracking MPP at different irradiance levels was analyzed for variation in parasitic resistance. The influence of converter as well as converter parameters on system behavior was investigated. It was found that the MPPT circuit reaches the maximum power point very fast followed by nearly free of start-up transient overshoot for reduced value of parasitic elements. For the similar load and at different weather conditions the MPPT efficiency was calculated. The maximum MPPT efficiency by using the coupled inductor SEPIC has been found 99.93%. The obtained simulation results validated the converter model in MPPT circuit.

Keywords: Photovoltaic (PV) energy systems, Parasitic burden, Maximum Power Point Tracking (MPPT), Single ended primary inductance converter (SEPIC), Magnetic coupling, Energy storage elements

Title of the Paper: Fuzzy Logic Direct Torque Control for Asynchronous Motor

Authors: José Luis Azcue, Alfeu J. Sguarezi Filho, Ernesto Ruppert

Abstract: In this article is proposed the Direct Torque Control (DTC) with Space Vector Modulation (SVM) based on Self-Tuning Fuzzy Logic(STFL) controller. This controller determines dynamically the load angle between stator and rotor flux vectors and in consequence the electromagnetic torque necessary to supply the motor load. The rule base for STFL controller is defined in function of the error e and the change of the error Δe of the torque using a most natural and unbiased membership functions (MF). Constant switching frequency and low torque ripple are obtained using SVM. Performance of the proposed DTC-SVM with STFL are compared with the performance of the same scheme but using PI controller in terms of several performance measures such as settling time, rise time and integral-of-time multiplied by the absolute magnitude of the error index (ITAE). The simulation results show that the proposed scheme can ensure fast torque response and low torque ripple in comparison with DTC-SVM with PI controller.

Keywords: Direct Torque Control, Space Vector Modulation, Fuzzy Logic Controller, Asynchronous Motor

Title of the Paper: Research on a Two-level Single-phase Active Power Factor Corrector Using Gray Prediction and Repetitive Control

Authors: Wang Nan, Yang Xi-Jun, Lu Fei, Li Yin-Long

Abstract: The traditional single-phase active power factor correction (APFC) has been widely used. There are two voltage levels between the output terminal of boost inductor and the negative rail of DC link, which correspond to turn-on time and turn-off time of IGBTs. IGBT is the normally used power device. One level is near zero, the other is approximately the positive Output DC voltage. Just due to this, no matter which control strategy is used, zero-crossing distortion of the mains current occurs theoretically that is inevitable. In the paper a novel two-level APFC topology is presented. It can completely eliminate the zero-crossing distortion in essence, at the time the current control strategies can be used. The two voltage levels between the output terminal of boost inductor and the negative rail of DC link are the positive Output DC voltage when IGBT is in on state and the negative Output DC voltage when IGBT is in off state, respectively. With regard to single-phase APFC’s control strategies, in order to generate the primitive driving pulse used for the next switching cycle, it is common that the data used in the current switching cycle is those measured in the previous switching cycle and the current switching cycle. It is inevitable that the method causes lagging control effects. Considering the function of gray prediction, the modulation of GM(1,1) is employed in order to achieve precise control. Thus the electrical quantities required in the next switching cycle can be accurately predicted, including the input AC voltage, the output DC voltage, the boost inductor current, the boost inductor current error and the output DC voltage error. It is also true that the single-phase APFC is powered by sinusoidal voltage, and the expected are DC voltage and sinusoidal current in phase with input voltage. It is inevitable that the method causes steady state errors, when using the traditional double loop control strategy, consisting of the voltage outer loop and the current inner loop. Therefore, the repetitive control strategy is utilized at the same time. The steady state errors can be eliminated and the dynamic characteristics can be improved by both adding voltage error in current switching cycle to the predicted current error and adding voltage error in current switching cycle to the predicted output voltage error. After analysis of the operation principle of the novel two-level APFC, a comprehensive control strategy based on gray prediction and repetitive control is designed. Then the comprehensive control strategy based two-level APFC is simulated and analyzed by means of MATLAB/SIMULINK and implemented. The obtained results are satisfactory and prove comprehensive control strategy.

Keywords: Power factor corrector, Two voltage-level, Zero-crossing distortion, Gray predictive control, Repetitive control, comprehensive control

Title of the Paper: Optimal PSS Design in a Multimachine Power System via Bacteria Foraging Optimization Algorithm

Authors: S. M. Abd-Elazim, E. S. Ali

Abstract: This paper proposes Bacteria Foraging Optimization Algorithm (BFOA) based power system stabilizer (PSS) for the suppression of oscillations in multimachine power system. The proposed design problem of PSS over a wide range of loading conditions is formulated as an optimization problem. BFOA is employed to search for optimal controller parameters by minimizing the time domain objective function. The performance of the proposed technique has been evaluated with the performance of Genetic Algorithm (GA) to demonstrate the superior efficiency of the proposed BFOA in tuning PSS controller. Simultaneous tuning of the Bacteria Foraging based PSS (BFPSS) gives robust damping performance over wide range of operating conditions in compare to optimized PSS controller based on GA (GAPSS) and conventional PSS (CPSS).

Keywords: Bacteria Foraging; Genetic Algorithm; Power System Stabilizer; Low Frequency Oscillations; Power System Stability; Multimachine System

Title of the Paper: Static and Transient Voltage Stability Assessment of Power System by Proper Placement of UPFC with POD Controller

Authors: Anju Gupta, P. R. Sharma

Abstract: Optimal Location of FACTS devices are very important for the rapid and successful operation because of high cost and circuit complexities. In this paper best location of UPFC (Unified Power Flow Controller) is obtained both for static and transient voltage stability enhancement of an IEEE 14 bus power system. The simulation is done on PSAT (Power System Analysis Tool-box) in MATLAB and optimal location is found out by Continuation Power Flow (CPF), VCPI (Voltage Collapse Proximity Index) and Fast voltage Stability Index (FVSI). The bus having lowest voltage is the critical bus and the line having largest value of index for maximum permissible load with respect to a bus is the most critical line referred to that bus. It is found that by properly placing UPFC loadability margin of the system has been increased considerably leading to improvement of voltage stability and stability index value decreases at each reactive load with the insertion of the device at right place. Transient stability analysis is also done for an IEEE 14 bus system with a three phase fault created at a bus. It is found from the time domain simulation that proper placement of UPFC increases the transient performance of the system by damping out the power oscillation under large disturbance conditions with less settling time.

Keywords: UPFC, FACTS, CPF, index, stability, PSAT

Title of the Paper: Analysis of a Photovoltaic System: AC and DC Power Quality

Authors: Daniele Gallo, Carmine Landi, Mario Luiso, Edoardo Fiorucci

Abstract: Since the penetration of photovoltaic systems in the electrical network is increasing, the need to register and model the contribution of these energy sources, in terms of generated disturbances, quality and amount of available power, is becoming a crucial issue for optimal management of grid. So, this paper, starting from data experimentally recorded on a medium scale photovoltaic system that is grid connected, performs a certain number of analyses both in AD and DC side, in order to better understand and explore the nature of electricity generation patterns of PV plants. In addition to the calculation and the comment of common steady state power quality indexes, also transitory situations are analyzed and discussed. Finally, an analysis of the electric power components according IEEE 1459 is performed and the results show that the application of that standard in this practical case presents some critical aspects.

Keywords: Voltage measurement, current measurement, power measurement, power quality measurement, photovoltaic plant, IEEE 1459

Title of the Paper: Risk Estimation of Induction Motor Fault in Power System

Authors: Mykola V. Kosterev, Eugen I. Bardyk, Volodymyr V. Litvinov

Abstract: In this article is proposed the method of induction motor fault risk estimation with the account of induction motor technical condition and EPS subsystem regime. For the induction motor technical condition appreciation is developed the fuzzy model. This model uses the expert knowledge and parameters, which could be obtained without the switching off the motor from grid. For the definition of induction motor fault probability in the case of accident in EPS subsystem probabilistic statistical approach is used. Obtained results could be used for organization the effective risk-oriented management of EPS subsystem for providing its reliability.

Keywords: Induction motor, EPS subsystem, fault, risk, probability, fuzzy model