Generators

Ocean energy is a well-invested renewable energy resource. Although proven technologies for energy generation from the ocean exist, most of the developed systems are yet to be combined with storage devices for later use. In this paper, three different energy conversion projects are described with prototypes for generating electricity from the ocean waves, currents and tides. Each project builds on the lessons learned from the previous, and involves incremental improvements towards the goal to store the generated electricity to be used afterwards. The small-scale prototypes reveal both promises and challenges of sustainable energy conversion devices and necessary storage technologies to be useful at large scale.

This paper addresses the attack modeling using vulnerability of information, communication and electric grid network. Vulnerability of electric grid with incomplete information has been analyzed using graph theory based approach. Vulnerability of information and communication (cyber) network has been modeled utilizing concepts of discovery, access, feasibility, communication speed and detection threat. Common attack vector based on vulnerability of cyber and physical system have been utilized to operate breakers associated with generating resources to model aurora-like event. Real time simulations for modified IEEE 14 bus test case system and graph theory analysis for IEEE 118 bus system have been presented. Test case results show the possible impact on smart grid caused by integrated cyber-physical attack.

This paper deals with the rough design of a Double-Stator Axial Flux Permanent Magnet Machine (DSAFPM) for a rim-driven Marine Current Turbine (MCT). The DSAFPM machine will be compared to a previously developed and realized Radial Flux Permanent Magnet Machine (RFPM); given the same rim-driven MCT specifications. For that purpose, a first-order electromagnetic design model and a thermal one are developed and used to compare active part mass, cost, and thermal behavior of the two machines.

This study investigates a task in which discrete and rhythmic movements are combined in a single-joint elbow rotation. Previous studies reported a tendency for the EMG burst associated with the discrete movement to occur around the expected burst associated with the rhythmic movement (e.g., [Exp. Brain Res. 99 (1994) 325; J. Neurol. Neurosurg. Psychiatry 40 (1977) 1129 Hum. Mov. Sci. 19 (2000) 627]). We document this interaction between discrete and rhythmic movements in different task variations and suggest a model consisting of rhythmic and discrete pattern generators that reproduces the major results. In the experiment, subjects performed single-joint elbow oscillatory movements (2 Hz). Upon a signal, they initiated a movement that consisted of a shift in the midpoint of the oscillation (MID), a shift in the amplitude of the oscillation (AMP), or a combination of both (MID + AMP). These shifting movements were performed either in a reaction time or in a self-paced fashion. The tendency for the EMG bursts associated with the discrete and rhythmic movements to synchronize was found similarly in all three tasks and instruction conditions, but the synchronization was most pronounced in the selfinitiated discrete movement. Reaction time was increased for the combined task (MID + AMP), indicating higher control demands due to a combination of discrete and rhythmic components. This EMG burst synchronization was reproduced in a model based on a half-center oscillator with activation signals that produce either rhythmic or discrete activity. This activity was interpreted as torques driving a simple limb model. Summation of discrete and rhythmic activation signals of the pattern generators was sufficient to simulate the EMG burst synchronization. Further, simulation data reproduced the modulation of the reaction time as a function of the phase of the discrete movement. D

Theoretical background included in part 1 of this work has shown the wide variety that the wind energy industry is offering in terms of electrical/electronic components and configurations. Though the first part of the course provides the student with an updated knowledge of the current technological status of the wind energy conversion systems (WECS), from the educational point of view the lectures are mainly teacher-centered and some relevant skills for electrical engineers are not excited. In spite of the breaking activities (videos, tests, challenging questions, etc), the role of the student keeps being somewhat passive. Aiming to overcome this shortcoming, this second part of the course places the student in the center of the teachinglearning process through hands-on work. The teacher becomes a consultant and the student has to build a wind energy system using simulation tools. Results of the experience prove that not only the motivation of the students is increased, but also the performance and acquisition of adequate competences.

We present a theoretical model developed for estimating the power, the optical signal to noise ratio and the number of generated carriers in a comb generator, having as a reference the minimum optical signal do noise ratio at the receiver input, for a given fiber link. Based on the recirculating frequency shifting technique, the generator relies on the use of coherent and orthogonal multi-carriers (Coherent WDM) that makes use of a single laser source (seed) for feeding high capacity (above 100 Gb/s) systems. The theoretical model has been validated by an experimental demonstration, where 23 comb lines with an optical signal to noise ratio ranging from 25 to 33 dB, in a spectral window of ~ 3.5 nm, are obtained.

A crucial challenge for scientific workflow management systems is to support the efficient and scalable storage and querying of large provenance datasets that record the history of in silico experiments. As new provenance management systems are being developed, it is important to have benchmarks that can evaluate these systems and provide an unbiased comparison. In this paper, based on the requirements for scientific workflow provenance systems, we design an extensible benchmark that features a collection of techniques and tools for workload generation, query selection, performance measurement, and experimental result interpretation.

| This paper presents a comprehensive study on the state-of-the-art and emerging wind energy technologies from the electrical engineering perspective. In an attempt to decrease cost of energy, increase the wind energy conversion efficiency, reliability, power density, and comply with the stringent grid codes, the electric generators and power electronic converters have emerged in a rigorous manner. From the market based survey, the most successful generator-converter configurations are addressed along with few promising topologies available in the literature. The back-to-back connected converters, passive generator-side converters, converters for multiphase generators, and converters without intermediate dc-link are investigated for high-power wind energy conversion systems (WECS), and presented in low and medium voltage category. The onshore and offshore wind farm configurations are analyzed with respect to the series/parallel connection of wind turbine ac/dc output terminals, and high voltage ac/dc transmission. The fault-ride through compliance methods used in the induction and synchronous generator based WECS are also discussed. The past, present and future trends in megawatt WECS are reviewed in terms of mechanical and electrical technologies, integration to power systems, and control theory. The important survey results, and technical merits and demerits of various WECS electrical systems are summarized by tables. The list of current and future wind turbines are also provided along with technical details. KEYWORDS | ac-ac; ac-dc; dc-ac; dc-dc power conversion; doubly fed induction generator (DFIG); fault-ride through (FRT); grid codes; low voltage (LV); medium voltage (MV); multilevel converters; permanent magnet synchronous generator (PMSG); power electronics; squirrel cage induction generator (SCIG); wind energy conversion systems (WECS); wind farms; wound rotor induction generator (WRIG); wound rotor synchronous generator (WRSG)

Recent technological advances have given rise to the popularity and success of cloud storage. However, the prospect of outsourcing an increasing amount of data to a third party and the abstract nature of the cloud foster the proliferation of security and privacy challenges, namely, the remote data possession checking. This paper addresses this critical security concern, when storing sensitive data in a cloud storage service, and the need for users to trust commercial cloud providers. It proposes a deterministic Proof of Data Possession (PDP) scheme based on Interactive Proof System (IPS) and an original usage of the GPS scheme. Our approach has several advantages. First, it supports public verifiability which releases data owners from the burden of a periodical verification. Second, it provides constant communication complexity, where the exchanged messages between the storage server and the client are composed of constant number of group elements. Third, our solution is efficient and provably secure, as it is resistant to the fraudulence of the prover and the leakage of verified data.

This paper briefly discusses the design of a lowcost, versatile and configurable error generator for PROFIBUS DP. Using a PROFICORE ULTRA oscilloscope trigger pulse, a small circuit designed around an Arduino MEGA 2560 disrupts messages on the industrial network, without adding an extra slave.

Around the world, conventional power systems are facing gradual depletion of fossil fuel resources, poor energy efficiency and environmental pollution. These problems have led to a new trend of generating power locally at distribution voltage level by using renewable/nonconventional energy sources like natural gas, biogas, wind power, solar photovoltaic cells, fuel cells, combined heat and power systems, micro-turbines and Stirling engines and their integration into the utility distribution network. Microgrid is essentially an active distribution network, which connects different renewable/nonconventional energy sources and various loads at distribution voltage level. From operational point of view, the micro-sources must be equipped with power electronic interfaces and control schemes to provide the required flexibility for ensuring their operation as a single aggregated system and to maintain power quality and energy output. Based on the above, the integration of a microgrid prototype for research of new control algorithms is necessary. In this work, a microgrid laboratory prototype is presented, which is composed by multiple items. This prototype allows tests for verifying energy quality in order to fulfil security requirements and integration restrictions.

The current version of the Concept Generator, an automated mathematically-based design tool, is studied in an effort to validate its general approach and establish research goals for further development. As part of the study, four undergraduate engineering researchers from the University of Missouri-Rolla and University of Texas at Austin execute a qualitative study of the software's effectiveness at producing useful design solutions. The students engage in several activities designed to test the capabilities of this early version of the software. A report of their results and analyses identifies the benefits and disadvantages of the software (and underlying method) as viewed at this stage of development. Furthermore, the design solution data collected by the undergraduate researchers is analyzed more quantitatively during a post-study investigation. Both the qualitative and quantitative studies indicate that the Concept Generator is a promising first step toward the creation of an effective design tool for the conceptual phase of design. Furthermore, the student reports on their hands-on experiences with the software identify strengths and weaknesses of this early version of the Concept Generator and help establish many avenues for further development of the design tool.

This paper presents the modeling of wind energy systems using MATLAB Simulink. The model considers the MPPT (Maximum Power Point Tracking) technique to track the maximum power that could be extracted from the wind energy, due the non-linear characteristic of the wind turbine. The model consists of wind generation model, converter model (DC-DC converter), and MPPT controller. The main contribution of our work is in the model of DC-DC converter (buck converter) which is developed in rather details, which allows the MPPT controller output (duty cycle) adjusts the voltage input of the converter to track the maximum power point of the wind generator. The simulation results show that the developed model complies with the theoretical one. Further the MPPT control shows a higher power output compared to the system without MPPT.

Equations are presented whereby the authors' previous paper1 is extended to the design of coils for heating magnetic loads, where the load remains in a fixed position relative to the coil during the heat. In heating magnetic materials, there is considerable variation in impedance of the coil circuit as the load temperature changes. The present paper first develops certain general principles by which a variable impedance circuit may be designed to absorb a predetermined maximum power, on the basis of constants determining the maximum and minimum impedance. Methods then are given by which these constants may be calculated for carbon steel loads of types SAE 1015 to SAE 1045, or their equivalent. In practice, these methods apply to most through heating and some surface heating applications. The accuracy of calculations is substantiated experimentally.

In this paper, various performance equations are derived from phasor diagrams of a three phase non-salient pole (cylindrical rotor) synchronous generator of known armature resistance and of ignored armature resistance for lagging, unity and leading power factor load. These equations are used to calculate the output parameters of non-synchronous generator and to plot the graphs of terminal voltage-armature current, torque angle-armature current, torque angle-terminal voltage, power-torque angle and torque-speed characteristics through simulation by MATLAB program for the purpose of illustration.

Fault current' is the flow of abnormal current through an improper path due to electric faults which causes enormous damages. In HVAC transmission system, Fault current due to electric faults is too large which affects the overall power system including-Receiving & Sending end bus, Transmission system, Load and even also the Power Generation Unit. HVDC transmission system dramatically reduces these effects, as the fault current due to electric faults is much lower, and only affects the individual faulty section of the overall transmission system. In favor of HVDC system, this paper presents a 'fault current' (due to asymmetric faults) analysis and comparisons between HVAC and HVDC transmission system. MATLAB (Simulink) simulation software is used to simulate both HVAC & HVDC power transmission system topologies. From the comparison of the simulation output-lower fault current, less fault effect, better performance & higher reliability is demonstrated for HVDC transmission system.

A photovoltaic (PV) system's output power fluctuates according to the weather conditions. Fluctuating PV power causes frequency deviations in the power utilities when the penetration is large. Usually, an energy storage system (ESS) is used to smooth the PV output power fluctuations and then the smoothed power is supplied to the utility. In this paper, a simple fuzzy-based frequencycontrol method is proposed for the PV generator in a PV-diesel hybrid system without the smoothing of PV output power fluctuations. By means of the proposed method, output power control of a PV generator considering the conditions of power utilities and the maximizing of energy capture are achieved. Here, fuzzy control is used to generate the PV output power command. This fuzzy control has average insolation, change of insolation, and frequency deviation as inputs. The proposed method is compared with a maximum power point tracking control-based method and with an ESS-based conventional control method. The numerical simulation results show that the proposed method is effective in providing frequency control and also delivers power near the maximum PV power level.

ABSTRACT The paper proposes the use of ultracapacitor storage device in order to support the mismatch between the available PV source power and microgrid load requirement. A realistic simulation scheme was implemented to evaluate the hybrid power system behaviour under varying microgrid load requirements. The operating performance were observed in steady state and transient conditions. The action of the ultracapacitor was pointed out, while the PV source operated at the maximum power point. Some discussions about the behaviour of the components and system operating characteristics were reported. The growing trend in both energy market deregulation and environmental preservation is forcing studies and applications of Distributed Generation (DG). DG, connected to local loads and distribution grids, is an extremely interesting issue. It offers the opportunity of constructing smart- and micro-grids, which are emerging as an integral feature of the future power systems. Microgrids are clusters of loads and micro sources operating as a single controllable power system. Microgrids can operate in parallel with the grid, as an autonomous power island, or in transition between grid- connected mode and islanded mode of operation. In the non-autonomous mode, the microgrid produces power while interconnected to the utility system. In the autonomous mode, the microgrid serves its electrical load without drawing power from the distribution utility. When possible, micro generation units are dispatched on the minimization of variable costs for service providing. So, real-time optimization in microgrids is performed through frequent adjustments of generator outputs to

This paper presents the development of a dual channel, air coupled Ultra-Wideband (UWB) Ground Penetrating Radar (GPR) targeting highway pavements and bridge deck inspections. Compared to most existing GPRs with a single channel and low survey speeds, our GPR possesses competitive features, including wide area coverage, high spatial resolution and operating capability at normal highway driving speed (up to 60 mph). The system has a two-channel microwave front end, a high speed (8 Gsps) real time data acquisition unit, a high throughput multithread data transmission and storage module, and a customized low-cost control element developed in a field-programmable gate array (FPGA). Experiments with different steel reinforcing bars establish GPR system performance.

Zydeco is a mobile and web based system that allows students to collect and annotate multi-modal data. With the support of Zydeco, students are expected to connect their learning experiences across different learning settings. In this case study, we shadowed four 7th grade students with different achievement levels from a science class and observed how they utilized Zydeco in a science center. We analyzed their data collected with Zydeco and their final project posters to explain how students connect learning experiences in nomadic inquiry.

The concept of Reliability-Centred Maintenance (RCM) is applied to the two wind turbine models Vestas V44-600kW and V90-2MW. The executing RCM workgroup includes an owner and operator of the analyzed wind turbines, a maintenance service provider, a provider of condition-monitoring services and wind-turbine component supplier as well as researchers at academia. Combining the results of failure statistics and assessment of expert judgement, the analysis is focused on the most critical subsystems with respect to failure frequencies and consequences: the gearbox, the generator, the electrical system and the hydraulic system. The study provides the most relevant functional failures, reveals their causes and underlying mechanisms and identifies remedial measures to prevent either the failure itself or critical secondary damage. The study forms the basis for development of quantitative models for maintenance strategy selection and optimization, but may also provide a feedback of field experience for further improvement of wind-turbine design.

In this paper, the large scale Unit Commitment (UC) problem has been solved using Dynamic Programming (DP) and the test results for conventional DP, Sequential DP and Truncation DP are compared with other stochastic techniques. The commitment is such that the total cost is minimal. The total cost includes both the production cost and the costs associated with start-up and shutdown of units. DP is an optimization technique which gives the optimal solution.

This paper presents the concept and design of a novel roadway microgrid. It operates as a smart microgrid that optimally utilizes the public right-of-way and roadway infrastructure to provide cost-effective, highly efficient, and reliable wind/solar electric power production, distribution, storage, and utilization. The fundamental unit of the microgrid is called the energy-plus roadway/traffic signal light (EPRTL), which contains a grid-connected wind/solar hybrid generation system installed on the pole of a roadway/traffic signal light for clean electric power production. The term "energy-plus" stands for annual energy consumption that is less than production. The generated electric power will be consumed locally by the roadway/traffic signal light; the excess power generated will be stored in batteries, optimally distributed in the microgrid, and supplied to the utility main grid. The deployment of the proposed roadway microgrid will dramatically change the role of the public right-of-way from an energy consumer to an energy producer, leading to energy-plus roadways. This will not only reduce the roadway agency operating costs but also generate new revenues for the Highway Trust Fund. The use of renewable electric power will also promote the development of green roadways.

The Society shall not be resporrsible for alatetIents or opinions 3daanced in pape,s or in=diecussion at meetings of the Society or of its Divlsinns or Sections or printed in its pubticat+oAS. M Discussion is printed only it the papor is published in en ASME Journal. Papers ate avaiiabe ]iC R from ASME for fifteen months after the meeting.

The Fuzzy Vault scheme was proposed as a means to improve the security of biometric technologies. However, the originally proposed Reed-Solomon (RS) decoding algorithm was not well understood and the CRC decoder, introduced as an alternative, remains the most popular in literature today. Despite its simplicity, CRC decoders contain significant flaws which motivate us to investigate the potential of RS decoders. In this paper, we discuss the role of RS codes in Fuzzy Vault and details a Berlekamp-Massey decoder as originally envisioned. However, due to the significant amount of erasures in a RS code word in Fuzzy Vault leading to poor decoder performance, we propose instead an alternate decoder based on the Euclidean algorithm, which considers the original approach to RS codes. Our results show that the RS decoder can achieve decoding speed significantly greater than any CRC decoders while maintaining informationtheoretic security, which are independent of advances in computing power. We also propose an improvement to the CRC decoder as a means to evaluate the security of a Fuzzy Vault and found that many existing implementations using CRC decoding are vulnerable to brute-force attacks.

The constant current controllers at high voltage direct current (HVDC) rectifier stations and the outer loops which set the reference to the current controller have potential to introduce negative damping on the nearby generating units. It is therefore vital to investigate the torsional interaction behavior between turbine-generator (TG) units and the HVDC systems over a frequency range of interest. In this paper, subsynchronous torsional interaction (SSTI) phenomenon for hydroelectric TG units with small generator-to-turbine inertia (GTI) ratios interconnected to an HVDC system has been investigated. The sensitivity of different system parameters, such as generating capacity and loading, DC power flow, AC network strength and current controller gains, towards electrical damping contribution is also examined. Hydro units with different shaft systems are examined for SSTI proneness by conducting perturbation analysis. The impact of hydroelectric TG units with different GTI ratios has also been examined by applying a three-phase to ground fault at the rectifier station. Simulation studies have been carried out in PSCAD R /EMTDC c environment. Due to lack of modal damping with relatively low decrement factor and logarithmic decrement, sustained and growing TG torque oscillations are noted for certain operating conditions of hydro units with small GTI ratios interconnected with an HVDC system.

In this paper, an acoustic feature extraction method based on mel frequency cepstral coefficients (MFCC) was implemented on FPGA for real-time respiratory sound analysis. The proposed technique was implemented using Xilinx System Generator (XSG) in MATLAB/SIMULINK environment. The feature vectors obtained with fixedpoint XSG implementation is compared to those obtained with on the floating-point MATLAB one using normal and wheezing respiratory sounds.

This paper presents an advanced control strategy for the rotor and grid side converters of the doubly fed induction generator (DFIG) based wind turbine (WT) to enhance the low-voltage ride-through (LVRT) capability according to the grid connection requirement. Within the new control strategy, the rotor side controller can convert the imbalanced power into the kinetic energy of the WT by increasing its rotor speed, when a low voltage due to a grid fault occurs at, e.g., the point of common coupling (PCC). The proposed grid side control scheme introduces a compensation term reflecting the instantaneous DC-link current of the rotor side converter in order to smooth the DC-link voltage fluctuations during the grid fault. A major difference from other methods is that the proposed control strategy can absorb the additional kinetic energy during the fault conditions, and significantly reduce the oscillations in the stator and rotor currents and the DC bus voltage. The effectiveness of the proposed control strategy has been demonstrated through various simulation cases. Compared with conventional crowbar protection, the proposed control method can not only improve the LVRT capability of the DFIG WT, but also help maintaining continuous active and reactive power control of the DFIG during the grid faults.

El estudio eléctrico de un aerogenerador superconductor para bajas velocidades de viento, se

puede desglosar en dos etapas: diseño eléctrico y construcción. Para desarrollar el diseño eléctrico del

aerogenerador, es necesario comprender ciertos conceptos de estos; la parte eléctrica principal del

aerogenerador es el rotor y el estator el cual es el generador de una FEM y por el otro lado los materiales

necesarios para su construcción tomando en cuenta las condiciones de operación de las máquinas eléctricas

superconductoras. En el presente trabajo, se mencionan los componentes principales de una maquina

eléctricas y los materiales necesarios para la construcción de prototipos que nos sirvan como referencia para

poder innovar en un futuro en otros aerogeneradores superconductores.

An innovative axial-field permanent magnet generator (AFPMG) with multiple stators and double rotors is designed and the structural and electromagnetic features are investigated. This generator has two permanent magnet (PM) rotors at the left - and right-hand sides of a double-sided stator. In order to get benefit from the magnetic flux produced at the outer parts of the generator, two other stators are also positioned near the PM rotors. AFPMG is mainly considered for wind energy applications and it has three phases. The electromagnetic features are characterized by finite element method (FEM) and the transient solutions are analyzed based on a proposed equivalent magnetic circuit model using three phases of induced emf at the coils having two different geometries. New AFPMG generates 80V at each phase for a constant velocity of 125 rpm and it has an efficient dynamics with low cogging torque values.

This paper investigates the possibility to use a power split electric driven continuously variable transmission as the core of a wind energy conversion system. The proposed power split transmission for WECS, called W-CVT allows to control the speed of the turbine rotor by keeping constant the speed of the electric generator. The W-CVT is constituted by a planetary gear set integrated with a small size electric machine. This device is installed between the step-up gearbox and a fixed speed fixed frequency electric generator. The limitation of the transmissible torque between the rotor and generator due to the introduction of the W-CVT could be preserve the system components during wind-gusts or electric faults on the grid side. This paper introduces the W-CVT concept, the dynamic model of a complete WECS transmission based on the W-CVT, a design criteria for sizing the CVT and some preliminary results obtained with this system. t t J J J J

Active contour model has been widely used in image processing applications such as boundary delineation, image segmentation, stereo matching, shape recognition and object tracking. In this paper a novel particle swarm optimization scheme has been introduced to evolve snake over time in a way to reduce time complexity while improving quality of results. Traditional active contour models converge slowly and are prone to local minima due to their complex nature. Various evolutionary techniques including genetic algorithms, particle swarm optimization and predator prey optimization have been successfully employed to tackle this problem. Most of these methods are general problem solvers that, more or less, formulate the snake model equations as a minimization problem and try to optimize it. In contrary, our proposed approach integrates concepts from active contour model into particle swarm optimization so that each particle will represent a snaxel of the active contour. Canonical velocity update equation in particle swarm algorithm is modified to embrace the snake kinematics. This new model makes it possible to have advantages of swarm based searching strategies and active contour principles all together. Aptness of the proposed approach has been examined through several experiments on synthetic and real world images of CT and MRI images of brain and the results demonstrate its promising performance particularly in handling boundary concavities and snake initialization problems.

Developing technology and systems for future power systems requires an evolutionary approach where Distributed Renewable Energy Resources can be seamlessly integrated in to the system. As the diversity of the generation mix increases, the need for advanced sensing, communications and control systems (so called "smart" grid technologies) in managing the real-time stability and operation security of the power system will increase. This paper focuses on the development of a mathematical framework and computational methodology that can be used to evaluate the stability and operational security of a power system in the context of stochastic hybrid dynamical systems, and propose an approach based on embedding and symbolic dynamics that can be used to analyze complex system behaviors by encoding the system dynamics into symbol strings.

Many wireless communication systems such as IS-54, enhanced data rates for the GSM evolution (EDGE), worldwide interoperability for microwave access (WiMAX) and long term evolution (LTE) have adopted low-density parity-check (LDPC), tail-biting convolutional, and turbo codes as the forward error correcting codes (FEC) scheme for data and overhead channels. Therefore, many efficient algorithms have been proposed for decoding these codes. However, the different decoding approaches for these two families of codes usually lead to different hardware architectures. Since these codes work side by side in these new wireless systems, it is a good idea to introduce a universal decoder to handle these two families of codes. The present work exploits the parity-check matrix (H) representation of tail-biting convolutional and turbo codes, thus enabling decoding via a unified belief propagation (BP) algorithm. Indeed, the BP algorithm provides a highly effective general methodology for devising low-complexity iterative decoding algorithms for all convolutional code classes as well as turbo codes. While a small performance loss is observed when decoding turbo codes with BP instead of MAP, this is offset by the lower complexity of the BP algorithm and the inherent advantage of a unified decoding architecture.

The multi-input integrated converters are synthesized from two or more single input converters to obtain a compact structure which has only one output filter and one control system. The proposed configuration is obtained from a hybrid buck DC-DC converter, with a high step-down conversion voltage ratio by adding a classical buck structure. Preliminary theoretical analyses, validated by digital simulations, come to support the proposed converter.

Distributed Generation (DG) is increasing in penetration on power systems across the world. In rural areas, voltage rise limits the permissible penetration levels of DG. Another increasingly important issue is the impact on transmission system voltages of DG reactive power demand. Here, a passive solution is proposed to reduce the impact on the transmission system voltages and overcome the distribution voltage rise barrier such that more DG can connect. The fixed power factors of the generators and the tap setting of the transmission transformer are determined by a linear programming formulation. The method is tested on a sample section of radial distribution network and on a model of the all island Irish transmission system illustrating that enhanced passive utilisation of voltage control resources can deliver many of the benefits of active management without any of the expense or perceived risk, while also satisfying the conflicting objectives of the transmission system operator.

The main purpose of this paper is to study the FPGA implementation of two 16 bit PN sequence generator namely Linear Feedback Shift Register (LFSR) and Blum-Blum-Shub (BBS). We have used FPGA to explain how FPGA's ease the hardware implementation part of communication systems. The logic of PN Sequence Generator presented here can be changed any time by changing the seed in LFSR or by changing the key used in BBS. The analysis is conceded out to find number of gates, memory and speed requirement in FPGA for the two methods. As Recently the field programmable gate arrays have enjoyed wide spread use due to several advantages related to relatively high gate density, short design cycle and low cost. The greatest advantage of FPGA's are flexibility that we reconfigured the design many times and check the results and verify it on-chip for comparing with others PN sequence generators.