Current Issue : April - June Volume : 2014 Issue Number : 2 Articles : 8 Articles
The design of electrical layout is a key element\r\nin the offshore wind farm planning. We present a novel\r\nelectrical layout design optimization method for offshore\r\nwind farms in this paper. The proposed method can be used\r\nto generate the network model based on fuzzy c-means\r\n(FCM) and binary integer programming (BIP) methods. It\r\ncan automatically allocate wind turbines to the nearest\r\nsubstations and obtain the topology structure of cables\r\nutilized to connect wind turbines or turbine and substation.\r\nThe objective of this optimization is to minimize the\r\ninvestment costs of cable connection and the transmission\r\npower losses. The results of case study clearly demonstrated\r\nthe feasibility of the proposed method and showed\r\nthat it can be used as a reliable tool for electrical layout\r\ndesign of offshore wind farms....
Fossil fuels containing hydrocarbons have been the prime source of energy for the transportation sector for ages. However their rapidly increasing consumption and consequent depletion of reserves clearly show that the end of Fossil Fuel Age is not very far .Thus production of Biofuels from plant materials is the major step towards harnessing one of the world�s most prevalent yet least utilized renewable energy source. A Breakthrough process for converting biomass into Biodiesel fuel promises a cheaper way to go Green. Commercially the production of Biodiesel production may employ transesterification by chemical method. Manufacturers have been utilizing edible oil for the production of biodiesel .Due to the high cost of such oils the cost of the final product is increased. This can be overcome by using low cost non-edible oil for the process. But such oils have high FFA content which reduce he productivity of the process. The enzymatic approach may be utilized to overcome this problem. The enzymes may be immobilized or used as whole cell biocatalyst for economizing the process as the enzymes are costly. Microalgae have been recently identified for their extraordinary potential for cultivation as an energy crop in this era of rising energy crisis and depletion of fossil fuels. Research must thus be focused on the production systems, extraction of oil in large scale and genetic modification of algal strains for better and feasible production of biodiesel....
This paper presents an improved thermal design\r\nmethodology for wind power converters. It combines analysis\r\nand experimental thermal design tools, including heat transfer\r\ncorrelations, flow network modeling (FNM), computational\r\nfluid dynamics (CFD), and experimental measurement techniques.\r\nMoreover, a systemic product development process is\r\nintroduced and an effective combination between the product\r\ndevelopment process and the thermal design methodology is\r\nachieved. The draftCFDmodeling at the initial design stage is\r\ndone. Furthermore, it uses the detailed CFD modeling and\r\nexperimental measurement techniques to provide a higher\r\ndegree of accuracy at latter design stages. The key advantage\r\nof the improved methodology is its emphasis on the use of\r\nvaried design tools, each of which is actively applied at its\r\noptimal point in the proposed product development process.\r\nThus, during the earlier stages of the product development\r\nprocess, the thermal risk is systematically reduced, and longterm\r\nreliability of products is maintained in a higher degree....
This paper proposes a new method for power\r\ntransmission risk assessment considering historical failure\r\nstatistics of transmission systems and operation failure\r\nrisks of system components. Component failure risks are\r\nintegrated into the new method based on operational condition\r\nassessment of components using the support vector\r\ndata description (SVDD) approach. The traditional outage\r\nprobability model of transmission lines has been modified\r\nto build a new framework for power transmission system\r\nrisk assessment. The proposed SVDD approach can provide\r\na suitable mechanism to map component assessment\r\ngrades to failure risks based on probabilistic behaviors of\r\npower system failures. Under the new method, both up-todate\r\ncomponent failure risks and traditional system risk\r\nindices can be processed with the proposed outage model.\r\nAs a result, component failure probabilities are not only\r\nrelated to historical statistic data but also operational data\r\nof components, and derived risk indices can reflect current operational conditions of components. In simulation studies,\r\nthe SVDD approach is employed to evaluate component\r\nconditions and link such conditions to failure rates\r\nusing up-to-date component operational data, including\r\nboth on-line and off-line data of components. The IEEE\r\n24-bus RTS-1979 system is used to demonstrate that\r\ncomponent operational conditions can greatly affect the\r\noverall transmission system failure risks....
The installation of wind energy has experienced\r\nrapid development during recent years. As a result,\r\nthe operation of power system can be greatly affected.\r\nTherefore, the operators of different countries have formulated\r\nthe grid codes which reinforce technical requirements\r\nfor wind power plants. In this paper, recent grid\r\ncodes published in different countries have been carefully\r\nreviewed. The basic requirements of active power control\r\nand reactive power compensation, both of which have\r\nparticular influence on wind power plants operation, are\r\nfocused on. Based on this review, it is understood that with\r\nthe increasing integration of wind energy, there is a\r\nworldwide trend to regulate the performance of wind\r\npower plants so that they can contribute to the stability and\r\nreliability of power system....
In this paper, a computation framework for\r\naddressing combined economic and emission dispatch\r\n(CEED) problem with valve-point effects as well as stochastic\r\nwind power considering unit commitment (UC)\r\nusing a hybrid approach connecting sequential quadratic\r\nprogramming (SQP) and particle swarm optimization\r\n(PSO) is proposed. The CEED problem aims to minimize\r\nthe scheduling cost and greenhouse gases (GHGs) emission\r\ncost. Here the GHGs include carbon dioxide (CO2), nitrogen\r\ndioxide (NO2), and sulphur oxides (SOx). A dispatch\r\nmodel including both thermal generators and wind farms is\r\ndeveloped. The probability of stochastic wind power based\r\non the Weibull distribution is included in the CEED model.\r\nThe model is tested on a standard system involving six\r\nthermal units and two wind farms. A set of numerical case\r\nstudies are reported. The performance of the hybrid computational\r\nmethod is validated by comparing with other\r\nsolvers on the test system....
The power grid in a typical micro distribution\r\nsystem is non-ideal, presenting itself as a voltage source\r\nwith significant impedance. Thus, grid-connected converters\r\ninteract with each other via the non-ideal grid. In this\r\nstudy, we consider the practical scenario of voltage-source\r\nconverters connected to a three-phase voltage source with\r\nsignificant impedance. We show that stability can be\r\ncompromised in the interacting converters. Specifically, the\r\nstable operating regions in selected parameter space may\r\nbe reduced when grid-connected converters interact under\r\ncertain conditions. In this paper, we develop bifurcation\r\nboundaries in the parameter space with respect to Hopftype\r\ninstability. A small-signal model in the dq-frame is\r\nadopted to analyze the system using an impedance-based\r\napproach. Moreover, results are presented in design-oriented\r\nforms so as to facilitate the identification of variation\r\ntrends of the parameter ranges that guarantee stable\r\noperation....
This paper presents a series of operating\r\nschedules for Battery Energy Storage Companies (BESC)\r\nto provide peak shaving and spinning reserve services in\r\nthe electricity markets under increasing wind penetration.\r\nAs individual market participants, BESC can bid in ancillary\r\nservices markets in an Independent System Operator\r\n(ISO) and contribute towards frequency and voltage support\r\nin the grid. Recent development in batteries technologies\r\nand availability of the day-ahead spot market prices\r\nwould make BESC economically feasible. Profit maximization\r\nof BESC is achieved by determining the optimum\r\ncapacity of Energy Storage Systems (ESS) required for\r\nmeeting spinning reserve requirements as well as peak\r\nshaving. Historic spot market prices and frequency deviations\r\nfrom Australia Energy Market Operator (AEMO) are\r\nused for numerical simulations and the economic benefits\r\nof BESC is considered reflecting various aspects in Australia�s\r\nNational Electricity Markets (NEM)....
Loading....