Please enter the words you want to search for:

EPE-PEMC 2002 - Topic 06: Power Electronics in Electrical Energy Generation, Transmission and Distribution
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2002 - Conference > EPE-PEMC 2002 - Topic 06: Power Electronics in Electrical Energy Generation, Transmission and Distribution
	[return to parent folder]
	3-Phase DSP Controlled Active Compensation Shunt System   By L. Frackowiak; M. Gwozdz; R. Porada	[View]   [Download]
Abstract: In the article a proposition of the high accuracy power electronics compensation system (compensator, active filter) is described. The system realises the rule of optimal compensation using power electronics current source. The control module utilises microcomputer unit on basis of floating point DSP and motion co-processor. The software and hardware parts of compensation system as well as tests results of compensator prototype are described too.
	A d.c.-a.c. Converter for Solar Power Applications   By S. Shirsavar; A. Wheldon; M. McCulloch; J. Knight	[View]   [Download]
Abstract: A d.c.-a.c. inverter for solar power applications is presented which requires only two fast switching IGBTs and two line frequency thyristors. The proposed scheme utilises smaller/cheaper passive components and does not require a line frequency transformer. The proposed topology is based on two Æuk converters which are connected back to back. The switching mark/space ratio of the high frequency IGBTs is then controlled in order to produce a sinusoidal output. The thyristors are switched at line frequency and the proposed scheme is expected to have improved efficiency, reliability and reduced costs compared to a standard inverter that utilises 4 fast switching IGBTs. A 50 W inverter based on this topology has been simulated and constructed. Excellent experimental and simulated results have been obtained; these are presented.
	A Flexible Test-Bench for Power Quality Conditioning Algorithms Testing   By I. Etxeberria-Otadui; U. Viscarret; S. Bacha; R. Reyero	[View]   [Download]
Abstract: This paper presents a test bench used for power quality conditioning applications. It is composed of a power structure, which includes a series and a shunt voltage source inverter (VSI) connected to the grid by coupling filters, and a control structure, which includes a Controller Board (DS1103 PPC) and the necessary software tools for the automatic implementation of control algorithms (Matlab/Simulink RTW). The test bench has been designed for the test of control algorithms for grid-connected voltage source inverters and in particular for their application as active filters. The main advantage of the test-bench is its flexibility. From the point of view of the topology, the test-bench permits to analyze the main topologies of active filters, operating as a series, shunt or a universal filter. From the point of view of the control algorithms, the control structure permits the implementation of new control algorithms easily and quickly, automatically from the control algorithms developed in simulation. The test-bench has been already used for the evaluation and test of different strategies for series voltage sag compensation implemented on a DVR (Dynamic Voltage Restorer). The paper presents some results and conclusions of this implementation as an example of application of the test-bench.
	A Low Cost 10 kW Fuel Cell Inverter for Domestic Power   By J. J. Nelson; A. M. Tuckey	[View]   [Download]
Abstract: The utilization of fuel cells for distributed power generation requires the development of an inexpensive inverter that converts a fuel cell's variable dc output into useful ac. To encourage this development the US Department of Energy and the IEEE setup and sponsored a national US student competition with a substantial first prize going to the lowest cost working fuel cell inverter: the 2001 Future Energy Challenge (FEC). This paper describes the work of the University of Wisconsin FEC Team. It discusses the topology used to achieve the said objective, the rationale used in choosing this topology, detailed component selection optimized to minimize cost, and detailed heatsink design. Finally some conclusions are made and a new total-system-approach design using a high voltage fuel cell is proposed to further reduce the cost of the inverter.
	A New Positive Sequence Voltage Detector for Unbalanced Power Systems   By P. Rodríguez; J. A. Gallardo; J. Bergas	[View]   [Download]
Abstract: This paper presents a fast, precise and robust positive sequence voltage detector working under unbalanced utility conditions. This detector utilizes a new “synchronous double reference frame PLL” that completely eliminates the existing errors in conventional three-phase PLL systems. In the paper, an analytical study and verification by simulation are performed.
	A Novel Stand-Alone Single-Phase Induction Generator Using a Three-Phase Machine and a Single-Phase PWM Inverter   By N. R. Abjadi; J. Soltani	[View]   [Download]
Abstract: A new type of single-phase stand-alone induction generator using a three-phase induction machine and a single-phase voltage-source PWM inverter is introduced. The generator scheme is capable of producing constant load frequency with a very well regulated output voltage. A small lead acid battery and a single-phase full diode-bridge rectifier are used to feed the inverter. The inverter feeds one of the stator phases. During the generator voltage build up, the battery is supplied by the inverter first, and after a while, it is replaced by a diode-bridge rectifier which is fed by the generator. The system steady-state and dynamic equations are derived and solved to obtain the performance characteristics of the generator scheme. A digital simulation study is carried out for a 2.2KW three phase induction machine. The simulated results obtained confirm that an output power of about 0.6 p. u. can be achieved by this generator.
	A Simple Maximum Power Point Tracking Control Employing Fibonacci Search Algorithm for Power Conditioners of Photovoltaic Generators   By M. Miyatake; T. Kouno; M. Nakano	[View]   [Download]
Abstract: Photovoltaic generation systems need Maximum Power Point Tracking (MPPT) control because the output power depends on the operating voltage and current. Therefore, many researchers propose various types of MPPT control methods. A new MPPT control scheme for power conditioners is proposed in this paper in order to realize higher efficiency with simple calculation. The line search algorithm with fibonacci sequence which is one of the optimizing method is employed for the MPPT. The modification of line search method is proposed for real-time operation. The method is verified with simulations and experiments. It is concluded that the scheme can respond fast variation of insolation and load condition.
	Active Power Filters for Suppression of Line Current and Voltage Harmonics   By T. Mlcak; P. Brandstetter	[View]   [Download]
Abstract: The power converters are typical load in distribution mains. Input circuits of these converters are often designed as controlled or non-controlled rectifiers, which consist of power semiconductor devices. The converter is non-linear load in the mains and its phase currents are not only sinusoidal. Current curves contain higher harmonics too, which unfortunately influences feed system. This influence causes non-harmonics curves of voltage. For reduction of the higher harmonics influence the filters compounded by inductors and capacitors are used. However these devices have many basic disadvantages. For example there is inner line impedance which making resonance circuit with sharp tuned resonance. All these disadvantages are possible to remove by using active power filters. The subject of this paper is the exhibit of parallel and serial active power filters and possibility their control. The control methods of the active power filters are described and experimentally proved. Simulation and practical results showing the dynamic state system's performance are presented.
	An Analysis Of Voltage Sags Ride-Through Methods For Modern AC Drives   By D. Raca; V. Katic; M. Hajder	[View]   [Download]
Abstract: This paper analyses voltage sags ride-trough methods for elimination of voltage sag effects in contemporary, inverter fed AC drives. The nature, amplitude and occurrence frequency of voltage sags are analysed. Negative effects on electric drives are discussed as well. Response of the components (contactors, control electronics and protective relays) of electric drives to voltage sags is considered in order to develop objective picture of the influence that sags have on electric drive. Finally, several methods for compensation of voltage sags effects are analysed and discussed using simulations and results reported in literature.
	Characteristics of High-speed Phase Shifter at Demand Side during Load Fluctuation   By K. Shutoh; E. Masada; K. Kameshima; J. Baba	[View]   [Download]
Abstract: High-Speed Phase Shifter (HSPS) is proposed to be installed in a distribution line for better voltage regulation performance and other functions instead of the Load Tap Changing transformer (LTC). In the proposed system, the one converter of HSPS is connected with the tertiary winding of three-phase three-winding transformer of the substation or Step Voltage Regulator (SVR) instead of connecting the LTC. The other converter is connected to the series transformer to inject a voltage to the transmission line. The voltage regulation range and the capacity of HSPS have been analyzed theoretically, and the simulations in which the simulation code ”PSCAD/EMTDC” is used have been carried out. HSPS was compared with the behavior of LTC in order to examine the voltage regulation by load fluctuation. As a result, it is shown that the voltage regulation range of HSPS is wider than that of LTC even-though the same winding is used, and HSPS is able to keep the voltage during load fluctuation at demand side. HSPS is a one of the solution to regulate the voltage of distribution system.
	Comparison of DC/DC Converter Topologies with, and without Transformer   By M. Pavlovsky; S. W. H. De Haan; J. A. Ferreira	[View]   [Download]
Abstract: This paper presents a comparison of Full-Bridge and Boost DC/DC converter topologies regarding high-power applications to enable choosing the topology that is most suited for up scaling. Two different versions of the full-bridge converter are included in the comparison, with and without galvanic insulation. Size as an indication for costs is the property that is used for the comparison. They are represented by basic component parameters. Utilisation ratios of semiconductors, energy contents and rms currents of capacitors and area-products of magnetic components are compared. This comparisons show that Full-Bridge converter with galvanic insulation is preferable for high conversion ratios, unlike Full-Bridge without galvanic insulation and Boost converter for low conversion ratios.
	Control Method of Power Units with Compensation for Unbalanced Load   By L. Schreier; J. Bendl; M. Chomát	[View]   [Download]
Abstract: The present paper analyzes operation of a power unit with a doubly fed machine under the condition of unbalanced voltage supply applied to the stator. A solution is presented how to increase the immunity of such a power unit against a negative-sequence voltage component and how to increase the controllability of the power unit. Examples of responses of the system to various disturbances in the power grid are discussed.
	Decoupling Multivariable GPC Control of UPFC-Based Power Flow Compensation   By T. Allaoui; M. A. Denai; M. Bouhamida	[View]   [Download]
Abstract: This paper investigates the application of generalized predictive control (GPC) to the unified power flow controller in order to improve the overall power system stability and performance under increased power flow conditions. These include an algorithm decoupling multivariable systems based on generalized predictive control. The performances of the controllers are evaluated under different operating conditions of the power system. The results demonstrate that decoupling MIMO GPC with proposed algorithm is very effective in improving the transient power system stability and very robust against variable transmission line parameters.
	Digital Control Circuit for Current-Fed Active Power Filter   By R. Strzelecki; K. Sozañski	[View]   [Download]
Abstract: This paper describes the proposed active power filter with the control circuit based on the modified instantaneous reactive power control algorithm. The control circuit was realized on floating point digital signal processor ADSP-21065L. In the proposed circuit an advanced current controller algorithm is employed. The active power filter circuit was build and tested. Some illustrative, experimental results are also presented in the paper.
	Digital control of a 1kW battery charger with a single IGBT switch in the grid   By S. Seguí; F. Ibanez; F. J. Gimeno; S. Orts; R. Masot	[View]   [Download]
Abstract: Commercial high-power battery chargers usually use controlled rectifiers with SCR semiconductors and phase control in the secondary winding of a transformer connected to the supply grid. Generally, currents handled by these semiconductors are very high, while the voltages are usually far below the nominal voltage of the electrical network. This paper proposes a battery charger with digital control of the charging current and which operates at the grid voltage level at low current. It can be implemented using a single IGBT switch. The system is digital controlled by a micro-controller that incorporates the technique of firing by pulse width modulation (PWM) controlled by a PID digital regulator with control of the charge current.
	Digital Control System Of A Synchronous Generator   By T. Idzotic; G. Erceg; N. Tonkovic	[View]   [Download]
Abstract: Voltage control system of a synchronous generator with four digital signal processors is presented in the paper. The entire digital control system includes also turbine governor and device for generator synchronization to an electrical network, which are not subject of this paper. Digital control can be performed on both separately excited and self-excited synchronous generators. The digital control system is made up by means of Analog Devices digital signal processors. A two-quadrant transistor’s (IGBT) chopper is used as a power converter for a generator excitier's excitation. Function of the voltage control system is experimentally verified on a generator with DC excitier and sliding rings.
	DSP-based Experimental Rig with the Doubly-Fed Induction Generator for Wind-turbines   By B. Rabelo; W. Hofmann	[View]   [Download]
Abstract: In this work the modelling and design for a wind generation control system using the doubly-fed induction machine and a DSP-based experimental set-up construction as well as part of its commissioning are presented. A DC-machine driven by a thyristor bridge emulates the windmill and is connected to the shaft of the generator. The latter is fed through its slip-rings by a back-to-back converter consisting of 2 IGBT-VSI connected with a DC-Link. The stator is directly connected to the grid. An LC-Filter at the output of the mains-side inverter supresses the harmonics and furnishes the required reactive power to the system. The system’s electrical losses are minimised through an optimal control strategy in which the reactive powers of both converters are simultaneously controlled. Due to the amount of required variables and measured quantities, as well as, the complexity of the control structure a powerful processing capability is needed. All of these features make a very interesting and challenging engineering task. Some simulation and experimental results will be shown and inherent problems of the commissioning will be addressed.
	Dynamic Performance of a Power Conditioner Applied to Photovoltaic Sources   By G. Grandi; C. Rossi; D. Casadei	[View]   [Download]
Abstract: A power conditioner connecting a photovoltaic power system to the electrical network is presented and analyzed in this paper. The power conditioner is controlled as an active filter. The stability and the dynamic behavior of the whole system is analyzed by introducing transfer functions. The analytical developments are confirmed by numerical simulations on a realistic circuit model implemented in the Simulink environment of Matlab.
	Excitation System with Microprocessor Based Twin-Channel Voltage Regulator for Synchronous Machines   By V. Cesic; S. Marijan; Z. Jurin; M. Kolic; M. Kajari	[View]   [Download]
Abstract: In this article a synchronous machine excitation system with microprocessor based twin-channel voltage regulator is presented. Block diagram of excitation system with digital voltage regulator is shown and the main parts of excitation system briefly described. Block diagram of twin-channel voltage regulator is shown too. The characteristically responses of excitation control system of synchronous generator in typical disturbances are presented.
	Filtering Properties of the Selected Double Tuned Passive Filter Structures Designed Using Genetic Algorithm   By R. Klempka; Z. Hanzelka	[View]   [Download]
Abstract: Designing of a double tuned passive filter could be considered as a multi-criteria optimisation problem, and Genetic Algorithms (GAs) could be applied to its solution. The paper presents seven different configurations of such a filter designed with a new version of the programme developed by the authors in the Matlab environment employing GA. Comparison of filters' frequency characteristics and evaluation of filtration effectiveness are presented.
	Fuzzy logic based control of a flywheel energy storage system based on an induction machine associated with wind and diesel generators   By L. Leclercq; B. Robyns; J.-M. Grave	[View]   [Download]
Abstract: The aim of this paper is to propose a control strategy of an induction machine based flywheel energy storage system associated with a diesel generator and a fixed speed wind generator. To control the power exchanged between the flywheel energy storage system and the AC grid, a fuzzy logic based supervisor is proposed with the aim to minimise variations of the power generated by the diesel generator. As the uncertainties on the induction machine parameters can reduce significantly the performance of the flywheel energy storage system, a fuzzy logic based multimodel field oriented control is proposed in this paper.
	High Voltage Multi-cellular Converters Applied to Transmission and Distribution   By D. Gerry; J. Clare; P. Wheeler	[View]   [Download]
Abstract: Multi-cellular converters are suitable for applications in the HV range. They are formed from the inter-connection of individual multi-level converter units. This paper describes the formation of such converter structures along with a classification system which allows the many topological variations to be individually identified. Power-flow and power-flow balancing within these converters is then addressed with attention given to particular methods of attaining balanced converter operation. results from analysis and simulation of power-flow in these topologies are discussed along with initial practical results from the laboratory prototype multi-cellular converter currently under development.
	High Voltage Multilevel Flying-Capacitor Type Inverter   By J. Pavelka	[View]   [Download]
Abstract: This paper describes one from methods using proper semiconductor valve connection and valve firing control for solving correct valve voltage distribution in multilevel inverter. A survey of used methods is given in introduction. Circuitry of two solutions for multilevel source is described generally in the first section. Second section is devoted to more detail description of a power part connection of five level flying-capacitor type inverter and possible switching states are determined. The goal for control strategy is analyzed and an influence of switching state on terminal condenser voltages is determined in the next section. A basic idea of control strategy for the terminal condenser voltage stabilization is suggested. Basic description of mathematical model for control strategy simulation and some results from its realization in MATLAB environment are given in the last section. Recommendations for further research works are given in conclusion.
	Investigations on the effect of field weakening on the efficiency of generators for wind turbines   By I. Nusimovich; J. G. Slootweg; H. Polinder; S. W. H. De Haan	[View]   [Download]
Abstract: In general field weakening in machines leads to a reduction of iron losses but also to a reduction of the pull-out torque and the push-over torque. With variable speed wind turbines the torque is decreasing more or less quadratic with speed, which offers the possibility to reduce the field in the lower speed range. The effect of field weakening on the efficiency and annual energy yield has been analysed.
	Neural Network-Based Controller for an Active Power Filter   By B. Swiatek; Z. Hanzelka	[View]   [Download]
Abstract: The need to eliminate a current and voltage distortion in power supply networks leads to developing of various compensator topologies and choice of different control algorithms that, to the possibly greatest extent, ensure their effective operation. The paper presents conception of an algorithm of a single-phase filter control system, in which neural network is employed both to estimation of non-active component of a load current and to control transistors of a VSI converter.
	On Implementing Recent Computer-Based Technologies to Develop Electric and Electronic Micro Industries   By A. M. Abdel-Hamid	[View]   [Download]
Abstract: This paper presents an overview of some well-developed computer-based technologies that can be used to create highly developed electric and electronic products. The implementation of recent technologies such as Real Time Workshop (RTW), Rapid Control Prototyping (RCP), and Hardware- in- the Loop (HIL) in order to develop electric and electronic micro industries will be detailed. However, beside Maple, Matlab, Mathematica, other novell computation environements suche as Modelica libraries will be addressed. These modern technologies can assist the the current establishments of an Egyptian industry in one of the most significant fields, specially if one considers the new challenging that will convoy the application of the world free trade agreement. The paper introduces powerful tutorials illustrating how to build a prototype of any electric or electronic circuit topology using these advanced tools. An industrial application will be demonstrated to indicate the benefits of rapid design, test, and analysis at the various industrial stages leading to a final product. The procedures used in this paper make use of the comfortable downloading the theoretical Algorithms to the Hardware, which enables an online monitoring of the required performances.
	Power Quality Enhancement And Harmonic Compensation Scheme For Asymmetrical Nonlinear Loads   By P. Kreidi; A. M. Sharaf	[View]   [Download]
Abstract: The paper presents a novel low cost dynamic shunt power filter scheme for commercial and industrial nonlinear (cyclical, arc type) asymmetrical loads. The smart filter is controlled by a dynamic on-line controller to regulate the switching duty cycle ratio (aD) for each asymmetrical half-cycle. The smart power filter is a new member of the family of smart power compensators and filters developed by the First Author.
	PWM Inverter Matches Generator Conductance for Maximum Power Transfer in Grid-connected Photovoltaic Systems   By F. Quarona; F. Spertino; F. Scapino	[View]   [Download]
Abstract: The paper proposes a method to determine the operating points of a grid-connected PV system based on intersection between generator and load curves and shows that, in particular, for the maximum power point on array characteristic be reached, the equivalent load conductance (ELC), transferred by PWM inverter to the DC side, equals the slope of the line tangent to generator I-V curve in this point. This technique is a very useful aid for designers to dimension circuit components for optimal system performance over full range of irradiance and temperature conditions, while in presence of parasitic parameters. Moreover it can help to exploit the inverter ability to track the maximum power point (MPPT) of the PV generator electrical characteristics without need of additional functional blocks and hardware. Proposed method is experimentally validated showing its effectiveness.
	Results of a Novel Failure Proof Control and Power Section for Rotating System Tie Frequency Converters   By A. Schmidhofer; O. Droegsler; H. Weiss	[View]   [Download]
Abstract: Nowadays control systems for rotating system tie frequency converters (RTFC) with a relative small rotor power converter require a very precise measurement of the rotor position and the rotor currents. The proposed concept improves the system robustness by employing a failure-proof rotor circuit control and a shoot-through proof IGBT inverter.
	Selection of the Parallel Active Filter's Power Rating When it is Applied in Distribution Systems   By M. Klytta; J. Bojarski; H. Supronowicz; R. Strzelecki; G. Benysek	[View]   [Download]
Abstract: To improve energy quality in distribution systems, many different solutions are implemented, for example: i) Active Power Filters (STATCOM); ii) Unified Power Flow Controllers (UPFC); iii) Unified Power Quality Conditioners (UPQC); iv) Interline Power Flow Controllers (IPFC). Interline Power Flow Controllers are classic series or series-parallel filters applied to given number of independent lines with common, for all lines, DC element. Their possible functions are enlarging and include power flow control between lines, reactive power compensation and distribution system's stability improvement. In the paper we will show that using probabilistic approach to the distribution system we can considerably decrease power rating of the Parallel Active Power Filter's when it is a component of the Interline Power Flow Controller’s and in situation when it stands alone.
	Self-commutated Flicker Compensator applying Flat-packaged IGBT   By K. Fujii; S. Konishi; M. Kato; K. Uto	[View]   [Download]
Abstract: Self-commutated Flicker Compensator: SFC, which compensates a voltage flicker and reactive power, is supposed to be of lower cost, smaller size, and higher efficiency. A SFC applying GTO can achieve a high ability of flicker suppression, but it is of high cost and requires large space because of many components, such as snubber circuit, anode reactors, and large gate power source. Consequently we have developed the SFC applying Flat-packaged IGBT and achieved short-circuit protection without fuses. The SFC of 12MVA has been operating in the arc furnace plant since August 2001.
	Simple Direct Power Control of Three-Phase PWM Rectifier Using Space Vector Modulation   By M. Malinowski; M. Jasinski; M. P. Kazmierkowski	[View]   [Download]
Abstract: This paper proposes a novel and simple direct power control of three-phase PWM rectifiers with constant switching frequency using space vector modulation (DPC-SVM). The active and reactive power is used as the pulse width modulated (PWM) control variables instead of the three-phase line currents ever used. Moreover, a line voltage sensors are replaced by virtual flux (VF) estimator. Theoretical principle of this method is discussed. The steady state and dynamic results of DPC-SVM that illustrate the operation and performance of the proposed system are presented. It is shown that DPC-SVM exhibits several features as: simple algorithm, good dynamic response, constant switching frequency and particularly provide sinusoidal line current when supply voltage is no ideal. Results have proven excellent performances and verify the validity of the proposed system.
	Simulation Study on Enhancement of Maximum Power Transfer Capability of Long Transmission Line With Midpoint Sitting STATCOM for Voltage Support   By S. Kincic; A. Chandra; Z. Huang; S. Babic	[View]   [Download]
Abstract: Impending deregulation of electrical energy and rising demand coupled with limitation in available neighboring resources has forced the energy planners to transmit more power from remote resources through existing long transmission lines. Loading of long transmission lines is limited due to voltage and stability issues. A thoughtful engineering option to increase power transfer capability over existing lines and to enhance voltage profile is to add the FACTS devices along the line providing voltage support. If one such device is sited at the midpoint of the line, the electrical length of the line is halved and power transfer can be substantially increased. STATCOM (Static Var compensator based on power converters) can significantly contribute to the cause. In this paper we investigate benefits of the STATCOM when installed for voltage support at mid point of long transmission line. By exploiting its possibility of fast response, the STATCOM significantly enhances transient stability limit of the power system, enhances voltage profile and increases maximum transferred power. In this work a detailed numerical simulation is carried out based on HYPERSIM, a real time digital simulator and software, to evaluate how much power transfer with respect to steady state and transient stability limits, can be increased through long radial line when a STATCOM is sited at the midpoint of the line providing voltage support.
	Single Phase Active Power Line Conditioners - without Transformers   By R. Strzelecki; G. Meckien	[View]   [Download]
Abstract: The article introduces structures at one-phase Active Power Line Conditioners. Mainly they are structures with minimum number of transistors. The conditioners like that can function as active series-parallel filters which reduce influence of a non linear load power supply, correct quality power supply that was delivered to the load and fitting parameters of supply network to required parameters by load. Finally the article contains selected results of simulation researches for the transformerless structures. Simulation researches have been done by the use of TCAD software. Also the article contain a few of waveforms which are the result of the laboratory model tests.
	Sliding Mode Control and Robust Analysis of Parallel Hybrid Filters   By O. Bachelier; J. Bosche; S. Tnani	[View]   [Download]
Abstract: In this paper, the authors propose a novel control strategy of active hybrid filters. Sliding mode control is introduced to allow active filtering of load harmonics and active damping of passive filter connected in parallel with the active filter. When connected in power grid, the complete system is adjusted to prevent the risk of resonance as well as harmonic filtering. A complete modelling of the system is achieved and robustness of the control law is analysed. Complete simulation of the system validates efficiency of the control law.
	Specification Guidelines to Improve Power Quality Immunity and Reduce Plant Operating Costs   By R. Lawrence; B. Moncrief	[View]   [Download]
Abstract: There are many useful IEEE and IEC standards that support the design of industrial plants. This paper brings relevant Power Quality (PQ) standards information together and provides recommendations for specification text in each aspect of PQ. The recommended text associated with single and three phase sags is not yet not yet covered in current standards. Circuit configurations for cost saving solutions are provided.
	Three-Phase Shunt Active Power Filter Using IGBT Based Voltage Source Inverter   By S. Milun; T. Kilic	[View]   [Download]
Abstract: In this paper a three-phase shunt active power filter for current harmonics cancellation by injecting a current waveform in power system is proposed. Power stage of the proposed active filter is realised using three serial inductance, three-phase IGBT based current controled voltage inverter with two symmetrical capacitors on dc bus. Three independent hysteresis controllers on the base of current references are used to generate switching signals for inverter transistors. The current references are obtained by taking the difference of load current and its fundamental harmonic. For fundamental harmonic determination with no time delay a combination of digital predictive filter and low pass filter is used. The simulation and experimental results illustrate the active power performance in power system with the nonlinear load.
	Unified Power Flow Controller (UPFC) and its Effect over an Uncompensated Parallel Line   By L. Cera Zanetta; R. L. Vasquez-Arnez	[View]   [Download]
Abstract: At present, several studies focusing the steady-state behaviour of the UPFC, mainly in radial systems, have been carried out. However, there is little literature examining its effect and interaction with the network. The present paper initially shows a brief analysis of both the series injected voltage and the shunt reactive current, which is based upon the d-q coordinates. Thereafter, the UPFC capability for controlling the transmittable power flow in a transmission line, where it has been implemented, and its simultaneous effect and control over an inflexible parallel line, are analysed. The simulations performed ratify the UPFC capability in increasing and modifying the power flow through a specific route. The EMTP program constituted the main tool for most of the results shown along the work.
	Utilisation of Renewable and Waste Energy by Turbine-Generator System in Disperse Power Plants   By T. Ruzsanyi; D. Bereknyei; W.-R. Canders; R. K. Jardan; I. Nagy	[View]   [Download]
Abstract: The paper analyses the viability of a system that makes it possible to generate electric energy by utilising renewable and waste energies. Attention is focused on the economical aspects of the system with various primary energy sources taken into account: solar and geothermal energy and the energy that can be obtained during gas and steam expansion. The system studied is basically feasible in the low power range, up to 100 kW but the fields of application are wide, thus the system typically fits in the idea of disperse power plants (DPP).