In this book, Enhancement of power quality by means of LVRT capability of wind farm driven by PMSG is presented. Nowadays the share of power using wind generation is increasing continuously in all over the world; hence penetration of wind power in to grid is also increasing. The grid connection condition of the wind turbine is more important and Cascading effect should be avoided; wind turbine should stay connected to grid during grid disturbances. Connecting wind farm to grid is difficult and challenging task for the system operators as there are many connection requirements as a part of Grid Codes. One of the dynamic requirements mentioned in grid code is Low voltage ride through capability. It also presents control of reactive power to satisfy grid code requirement using STATCOM. Simulation results show the real power, reactive power with STATCOM and without STATCOM.
The fast growth of wind generation has led to concern about the effect of wind power on the transient stability of the electric grid. New studies must be performed in order to evaluate the behaviour of the wind farms after severe faults and improve the design of the wind farms in an efficient and economical way. Under such circumstances, the most demanding requisite for wind farm is the Fault Ride-Through (FRT) capability. Wind farms connected to high voltage transmission system must stay connected when a voltage dip occurs in the grid, otherwise, the sudden disconnection of great amount of wind power may contribute to the voltage dip, with terrible consequences. Therefore, the dynamic and transient analyses of wind generators are necessary. This book proposes some methods with suitable control strategies for wind power application that helps wind farms to be connected during grid disturbances, achieving the grid code provisions in both steady and transient conditions. The results in this book can be significant in understanding the transient stability phenomena of fixed and variable speed wind turbines and also in designing of wind farms based on transient stability requirements.
Due to random variations of wind speed, output power of a wind turbine generator fluctuates continuously. The power and voltage quality of a wind power system consisting of Induction Generator (IG) based wind turbine (IGWT), IGWT with voltage control device and Doubly Fed Induction Generator (DFIG) based wind turbine (DFIGWT) are presented in this work. Blade pitch angle control to limit the output power at turbine’s nominal power is also presented. It is reported that the DFIG-based wind turbine system can smooth the output power and also maintain the terminal voltage at a desired level, as DFIG with two back-to-back voltage source converters that use IGBTs and a capacitor acts as the DC voltage source has real and reactive power control abilities. The comparative results show that DFIGWT-based wind farm (DFIG_WF) has the best response, IGWT-based wind farm (IGWF) with voltage control device has better and IGWF has the worst response. Results indicate that the fluctuation of output power at higher rated rotor speed (near turbine’s base wind speed) and terminal voltage are almost nil for DFIG_WF. All the analysis were carried out using SimPowerSystem tool box in MATLAB.
The grid codes require taking into account the reactive power of the wind farm/park in order to contribute to the network stability, thus operating the wind farm as active compensator device. This book gives a comparative study of stabilizing wind farms using flexible ac transmission systems (FACTS) units like the (Static Synchronous Compensator) STATCOM and the variable speed wind turbines like the Doubly Fed Induction Generators (DFIGs) during wind speed change and grid fault. Both systems can provide reactive power to the wind farms during dynamic and transient conditions. Simulation analyses were carried out in laboratory standard simulation software called power system computer aided design/electromagnetic transient including DC (PSCAD/EMTDC). The simulated results show that the wind farms could be effectively stabilized with both systems. However, the cost is reduced with the DFIGs system because, apart from generating electric power during steady state,it can also provide reactive power through its frequency converters to stabilize the wind farms without the need of an external reactive power compensation units like the STACOM.
Climate change and growing concern of limited fossil fuel reserves and prices have led to the necessity of creating renewable and sustainable energy sources. Recently, Wind energy is attracting more attention from researchers and even utilities due to its benefits as a clean and abundant source of energy. Moreover, it is worth noting that Power demand has increased substantially while the expansion of power transmission lines has been severely limited due to inadequate resources and environmental restrictions. As a consequence, some transmission lines are heavily loaded and the system stability becomes a serious problem. FACTS controllers have been used for solving various power system control problems, enhancing power system stability in addition to their main function of power flow control. In this book a comprehensive and intensive study of a wind farm connected to the grid has been proposed. The aim of this book is to investigate the system stability of a wind farm connected to medium voltage grid in different operating conditions and to investigate the behavior of the system when using a Static Var Compensator (SVC) and Static Synchronous Compensator (STATCOM).
A Hybrid Multilevel H-bridge converter based transformerless static synchronous compensator employing an effective modulation control technique is Proposed.The main objective is to maintain the voltage stability by compensating the reactive power in the transmission system.A new control strategy is proposed in this paper for dc voltage regulation and also to isolate the voltage and current harmonics in the transmission system.This new STATCOM in each phase consist of series connection of a high-voltage H-bridge converter operating at fundamental frequency and a low-voltage H-bridge converter operating at 5 kHz.The fundamental parameters are controlled with the help of Fuzzy Logic controller.In order to effectively improve the immunity capability of this novel control strategy to the uncertainties in system parameters, two fuzzy PI controllers are separately employed to maintain the voltages at the PCC and to simultaneously regulate dc-link voltage. The hybrid multilevel STATCOM which can be used at the point of common coupling (PCC), for improving power quality is modelled and simulated using proposed control strategy.
My book is about the protection and control in the CIGRE low voltage distribution grid and the networks like this in case of large scale renewable energy integration. As the stochastic nature wind and solar power creates problems of voltage and power oscillations in the main grid and also RE integration presents problems in the protection of the networks. Some of these problems have been solved in this book. Also the mitigation of the balanced and unbalanced voltage sags have been presented in this book. The issues of the islanding and reconnection have also been discussed here and the constancy of the voltage and the frequency in the islanded Micro Grid (MG) has also been maintained by using STATCOM controllers
The purpose of this book is to show the different prediction possibilities in wind speed by using the artificial neural network for the time shift wind speed prediction using Matlab program. Additionally using the WASP program for sizing a suggested wind farm and do the prediction possibilities horizontally and vertically. Also the steps for sizing the suggested wind speed prediction tool were included. And the pre-steps to be done for the input data before processed by the proposed ANN tool. An error calculation was also carried out in order to evaluate the performance of the suggested ANN prediction tool and to show the improvement of errors with the different approaches. The best root square error was /0.0505/. Information about wind data were obtained by the help of the Syrian research center. A complete 100 [MW] wind farm module was studied using the WASP program, with the help of “Grid integration of Al Haijana Wind Park” study [ ]. V90 turbine from Vestas was selected for this wind farm. A detailed study for the awake effect was done using the WASP program.
Exploring background information about potential wind energy and future wind project in Turkey and World. Turkey has very quality wind power potential. Nevertheless, benefitial from wind power up to 5 % of total wind potential. Analysing to take accounts of the wind data measured as monthly time in the windy areas which is taken by EIE in 2014. In addition providing that legilation and application mechanism in Turkey. The other part is that choising site for wind farm and comparison of wind turbines so choosing to build right turbine for wind farm. The final and main part is CFD analysis for Band?rma windfarm project therefore, it finds out energy output by using porous disc method instead of wind turbines and get the best efficient and wind speeds vectors, wind direction and pressure in area.
Biosorption is a cost effective process by using biomass raw materials which are either abundant or wastes from other industrial operations for decontamination of ionic pollutants, such as heavy metal ions. This work focused on the investigation of potential of "Polysiphonia nigrescens" biomass for removal of Cr(III) ions from aqueous solution. Experimental parameters affecting the sorption process such as pH, contact time, initial metal ion concentration and biomass dosage were studied. The equilibrium sorption data were evaluated by isotherm models. The experimental results were also analyzed in terms of kinetics approach. The functional groups involved in metal sorption were examined using Fourier transform infrared spectroscopy (FTIR), X–ray absorption spectroscopy (XAS) and X–ray photoelectron spectroscopy (XPS) analysis. The morphological changes of P. nigrescens before and after metals sorption were explored by microscopy techniques. Finally, desorption studies were made using dilute desorbing agent.The present report indicates that "P. nigrescens" is an effective and economical adsorbent for the removal of Cr(III) from wastewaters.
The study was conducted with farmers where the author used new technology for the extension of the information using Information and Communication Technology (ICT) for increasing farm productivity of Bangladesh. Bangladesh Agricultural University Extension Center (BAUEC) has been using the ICT tools for supplying farm information to the farmers at the present time and this is a new dimension in Bangladesh agricultural sector. According to the design of this work, author developed her research instruments to find out the impact of ICT mediated extension services on farm productivity as well as their awareness on ICT tools in day to day farm life.
Due to the environmental and economical concerns, it is expected that a huge number of wind farms are going to be connected with the existing networks in the near future. However, the wind being intermittent sources of power, cannot meet the load demand all of the time. Wherever intermittent power sources reach high levels of grid penetration, energy storage becomes one option to provide reliable energy supplies. Therefore, this book deals with different approaches to stabilize a grid-connected wind farm.Among the various energy storage devices SMES is one of the options to provide reliable and fast response energy to the grid. These devices can help to make renewable energy more smooth and reliable, though the power output cannot be controlled by the grid operators. They can also balance micro grids to achieve a good match between generation and load demand. Also, it can significantly improve the load availability, a key requirement for any power system. The energy storage, therefore, is a desired feature to incorporate with renewable power systems, particularly in stand alone power plants. Thus this book investigates different methods to use SMES for stabilizing windfarm.
Generation of electricity using wind power has received considerable attention in recent years & short circuit current contribution of wind turbine has not received much attention so far. wind power plants do not have independent back voltage, they behave as transient sources of fault current during the critical time range.STATCOM improves power quality after the fault. The essential feature of STATCOM is that it has ability to absorb or inject reactive power to the system moreover restoring the stability of the power system having wind farm after occurring severe disturbance such as short circuit fault.