Renewable Energy

The performance of a proton exchange membrane (PEM) fuel cell is greatly affected by the operating parameters. Appropriate operating parameters are necessary for PEM fuel cells to maintain stable performance. The results indicate that the cell performance can be enhanced by increasing operating temperature. The anode humidi?cation has more signi?cant in?uences on the cell performance than the cathode humidi?cation, and the best performance occurs at moderate air relative humidity while the hydrogen is fully humidi?ed. In addition, the fuel and oxidant flow rate proves to be influencing the cell performance. Based on these conclusions, several suggestions for engineering practice are also provided.

Offshore wind and tidal current are of the most common energy resources for generating electricity in the near future because of the oil problems (crises and pollution). The dynamic model of the offshore wind and tidal current are very important topic for dealing with these renewable energies. This paper describes the overall dynamic models of tidal current turbine using three different types of generators (doubly fed induction generator (DFIG), squirrel cage induction generator (SCIG) and direct drive permanent magnet synchronous generator (DDPMSG)). The state space for all types of the generators of these two types of turbines are concluded. All models are validated using a common property of the generator for the validation.

This applied research deals with not only the preparation and characterization of nano-structured solar fins but also the evaluation of efficiency of solar collector integrated with the nano-structured fins. In this connection, fins in standard sizes were procured and the nano-structured coating with the composition of carbon and aluminium oxide was deposited on them. The coatings on fins were characterized through X-ray diffraction (XRD) and scanning electron microscopy (SEM) and the fins were subjected to thermal analysis. The coated fins were integrated in a solar collector and thermal performances of the collector were experimentally found for a set of inlet temperatures of working fluid. The overall thermal performance of the collector was calculated through a graph that was generated as per standard specifications. It was found that the sizes of the grains in the coating were in nano range with orthorhombic structure. It was also found that the temperature enhancement on the solar fins with carbon and aluminium coating of 75:25 compositions in stagnant conditions had the maximum value 109.1?. While the maximum instantaneous thermal performance was found to be 73%, the overall thermal performance of the solar collector was found to be 70%. On the basis of the generated results in the present investigation, it could be concluded that nano-carbon and aluminium oxide coated fins would be used in solar collectors so as to reap enhanced thermal performances.

This paper presents a method for calculating optimum values of stabilizing proportionalintegral- derivative(PID) controller for interval plants using particle swarm optimization(PSO) technique. This method is based on plotting the stability boundary locus in the (Kp,Ki)-plane for fixed Kd and then compute the stability region of PID controllers. Once the stability region of Kp,Ki locus is obtained, the best possible PID controller parameters are computed using PSO technique. The proposed method has got advantages like, It does not require sweeping over the parameters and also does not need a linear programming to solve set of inequalities over existing methods. To show the efficacy of the proposed method, a typical unstable fixed coefficient and interval plant is considered and simulated in MATLAB.The simulation results obtained by the proposed method are successfully verified.

Gearboxes are widely applied in power transmission lines, so their health monitoring has a great impact in industrial applications. In this study we present fault diagnosis and classification method for intelligence condition monitoring of MF285 final drive. Broken and worn tooth face of ring gear of gearbox as two common faults of gears are studied. The vibration signal was collected by an accelerometer type VMI102 from the experimental setup that was built for this the research. Each class had 150 samples that divided in two parts. 105and 45 samples for training and test data were considered. These signals were processed by Fast Fourier Transform (FFT) signal processor for made better decomposition to feed the feature extraction and feature selection method. 30 features were extracted from frequency domain of vibration signals. Stepwise Backward Selection was employed as feature selection technique for select the better features for the best fault detection result and increases the accuracy degree of fault detection and classification. 9 features selected were used as input to Support Vector Machine (SVM) for fault classification. Least Square Support Vector Machine (LS-SVM) was applied for SVM. Results showed that the accuracy for train and test data was about 99.05% and 95.56% that greater than 85% so that’s acceptable. Also results show the ability and high quality of this procedure for planter gearbox health monitoring.

Renewable energy sources has drawn attention around the world due to the rapid industrial development and growing population .In order to make the effective use of renewable energy to meet the global energy consumption, it is important to develop high performance, low cost and economically friendly energy storage devices. Since conventional capacitors have some inadequacies such as small energy density (i.e., <0.05 Wh/kg) for many applications which require a large amount of energy storage or delivery,supercapacitors has emerged as new storage device due to their high durability during its long charge – discharge cycles. Supercapacitors are governed by the same fundamental equations as conventional capacitors, but utilize higher surface area low resistance electrodes and thinner dielectrics to achieve greater capacitances. Properties of supercapacitors depend both on the technique used to prepare the electrode and on the current collector structure. Carbon Materials in different forms such as carbon fibers, carbon aerogels, activated carbon, carbon nanotubes and graphene are the attractive electrode materials for supercapacitors. The incorporation of nanomaterials as electrodes help to control the surface area as well as porosity which results in improved performance, greater efficiency and life time of the super capacitors .This recent technology improvement enabled supercapacitors as an alternative to pulsed batteries for applications in industry and telecommunication equipment. This review focuses on the taxonomy of supercapacitors, explores principle and theory of operation, dependence on different electrode materials on supercapacitor output and their application in the present world.

This paper presents the modeling and design of State Feedback with Integral controller on Twin Rotor MIMO System. In this two SISO systems are considered (i) main rotor (ii) tail rotor. Main Rotor is used to control the pitch axis and the Tail Rotor is used to control the yaw axis. By using the state feedback the both the axis are controlled as desire. The main aim of this paper is to compare the control performance between State Feedback and PID controller that is designed with Relay feedback method. The entire work has been carried out in MATLAB environment and the performance is compared in the terms of settling time, peak overshoot, offset and overall performance. The regulatory response of the system is also presented.

Due to the convincing revolution in power electronic technology and the growing concern about greenhouse effect that is intensified due to the burning of fossil fuels, wind power generation is significantly increasing globally. Transmission line operators developed various grid codes that require wind turbines to remain connected to support power grids during intermittent disturbance events which motivated researchers to investigate the impact of various grid disturbances on the overall performance of the wind energy conversion system (WECS). No attention, however, has been given to investigate the impact of voltage source converter (VSC) faults on the low voltage ride through (LVRT) of the DFIG-based WECS. In this paper, the impact of a fire-through fault when it takes place within the RSC and the GSC on the LVRT capability of the DFIG are investigated. A STATCOM controller to mitigate the effects of these faults is proposed. The DFIG compliance with recently released LVRT grid codes under the studied faults with and without the STATCOM were examined and compared. Simulation results indicated that fire-through faults have a serious impact on the DFIG voltage profile, especially when they occur in the GSC. The proposed STATCOM controller is effective in improving the dynamic performance of the DFIG during the studied faults and hence the connection of wind turbine to the grid can be maintained.

The main objective of the current proposed work is to emphasizes on the fact that there is a dire need to discover novel bionic shapes for the urban wind turbine rotors which would dovetail with the cornered flow patterns and thereby enable the capture of the high kinetic energy existing in the vicinity of the cornered flow past a building in an urban terrain. And this clearly affirms the effectiveness of the urban wind turbines and its utility as a renewable source rendering us with an alternative and superior way of electricity generation.

The main objective of the current proposed work is to study the technical, environmental and economical feasibility of the implantation of co firing technology in a Biomass power plant with pulverised low rank coal. Co-firing biomass and coal increases the use of sustainable fuels without large capital investments, and takes advantage of the high efficiencies obtainable in coal-fired power plants. Fuel diversity is another advantage of biomass/coal co-firing. Co-firing reduces the need for a constant supply of biomass required as in a biomass power plant, and is a viable way to decrease the emissions of greenhouse gases and other pollutants from power-generating facilities. As a result, using renewable and sustainable energy resources, such as biomass co-firing, for electricity production exhibits great potential in the near future. The use of dedicated biomass feed stocks for electricity generation could help to reduce the accumulation of greenhouse gases. This work focuses on minimization of overall unit cost of electricity with a maximum performance.