Abstract: Discrete Cosine Transform (DCT) is commonly used in image compression. In the history of DCT, a milestone was the Distributed Arithmetic (DA) technique. Due to the technology dependency a multiplier-less computation was built with DA based technique. It occupied less area but the throughput is less. Later, due to the technology scaling, multiplier based architectures can be easily adapted for low-power and high-performance architecture. Fixed width multipliers - reduces hardware and time complexity. In this work, Radix 4 fixed width multiplier is adapted with DCT architecture due to low power consumption and saves 30% power. In order to reduce truncation errors caused during fixed width multiplication, an estimation circuit is designed based on conditional probability theory.
Abstract: This paper presents a PIR regulator using direct torque control strategy of grid connected wind turbine driven doubly fed induction generators (DFIGs) when the grid voltage is unbalanced. Under the unbalanced grid voltage condition, the stator voltage and current quality is strongly affected due to the negative and distorted components. It will be reducing the performance of other normal loads connected to the DFIG. That control scheme consisting of indirect matrix converter using DTC. To verify the value of the proposed control strategy, simulation results with 500 MVA DFIG topology are presented and discussed in the paper. Finally,the simulation studies are carried out on a 500 MVA wind-turbine driven DFIG system under unbalanced grid voltage conditions. All the results are validated by using PSCAD simulation.
Abstract: The pulse width modulation (PWM) strategy employed in the voltage source inverter (VSI) not only control the magnitude of the output voltage but also the quality. Performance evaluations of such strategies are done in terms of fundamental voltage, total harmonic distortion (THD), switching losses etc. (primary indices) and also in terms of acoustic noise, electromagnetic interference (EMI), harmonic spread factor, distribution of harmonic power etc. (secondary indices). Multilevel inverter (MLI) has become unanimous choice in medium and high power applications due to their superior performance compared to three level inverters. The conventional Sub-Harmonic PWM (SHPWM) scheme and its variations offer the output voltage spectrum with high intensity harmonic components around the switching frequency; it will end with cluster harmonic with high acoustic noise. The first objective of this paper is to investigate harmonic spreading effects of existing multilevel inverter (MLI) strategies. Secondly the developing innovative PWM strategies for MLIs based on modified reference and carrier functions, which were proved for superior the primary indices at three-level VSI. Thorough simulation study of Pulse width modulation strategies such as SHPWM, inverted sine carrier PWM, MWM PWM, third harmonic injection PWM, triplen harmonic injection PWM, analog space vector PWM, trapezoidal PWM and discontinuous PWM for a cascaded multilevel inverter, are presented with results of primary and secondary indices. Hence, the PWM strategies of MLI are evaluated for harmonic spreading effect first time and a guide line for a beginner to select the PWM scheme for MLI fed drive systems is stenciled.
Abstract: This project focuses on the enhanced and development of the direct torque controller of doubly fed induction generator (DFIG) with unbalanced and distorted grid voltage conditions. Real, reactive power and electromagnetic torque are improved by using the design and development of Analytical model, Finite Element analysis (FEM), Direct Torque Controller with active Crowbar circuit and network side converter. Finally fundamental, fifth and seventh order harmonics are removed by using Fast Fourier transform (FFT) and also determine Total harmonic distortion (THD) and Individual harmonic distortion (IHD). The simulation result is exposed using power system computer aided design (PSCAD).
Abstract: This manuscript discusses about the Parameter estimation of Induction motor by utilizing the soft computing methodologies that is by using evolutionary algorithms such as Genetic algorithm, Particle swarm optimization, Artificial immune algorithm to overcome the difficulties in the conventional method where we calculating the per phase equivalent circuit parameters from the No load test and Blocked rotor test which compromises in result in terms of accuracy of the result and also evaluated the accuracy of the different algorithm in estimating the parameters of the induction motor.
Abstract: Multilevel converters are effective means of reducing harmonic distortion and dv/dt of the output voltages, which makes this technology applicable to utility interface and drives. In this paper, Multilevel Converter for power conversion is proposed. The voltage balancing at the terminal is achieved through proper selection of switching states. The switching scheme is defined by Space Vector Modulation. A fuzzy controller need to be interfaced with the system using SVM for optimal voltage operation and error minimization .The main feature of the proposed SVM switching strategy is that it enables balancing voltages of the dc capacitors, with no requirement of additional controls or auxiliary devices and higher magnitude of ac-side voltage with reduced harmonic concept in the output waveform. The proposed idea is demonstrated in simulation to evaluate the validity of the concept in MATLAB.
Abstract: In process industries control of nonlinear processes like level process is a common problem. For these nonlinear processes, to have a good performance even in the presence of environmental changes, the controller must have the ability to adopt changes in plant dynamics. So a Model Reference Adaptive Control (MRAC) based on PID controller is designed. Main objective of this work is to design PID-MRAC to include adaptiveness and to give good steady-state and transient performance for coupled tank system both with interaction and without interaction. A Particle Swarm Optimization (PSO) algorithm is used to fine tune the PID controller parameters. Simulations are done to show the effective performance of PID-MRAC compared to simple MRAC applied to couple tank system.
Abstract: Renewable energy resources has given rise to the systems that transmit and distribute electricity. Recent developments in the wind energy as distribution generation systems in the distribution networks is gaining popularity as a new sources of energy. The integration of renewable energy in to the power system causes severe challenges for the control and protection of the distributed system. A careful operation and design of distribution systems with renewable energy resources should be carried out. This paper describes the dynamic modeling and simulation results of DFIG wind turbine during nonlinear loading. During nonlinear loading the overall performance gets considerably degraded due to the effect of negative sequence component and also the power produced by the DFIG gets considerably derated. To eliminate this effect a suitable control technique should be applied. Direct Power Control (DPC) scheme is implemented along with Proportional Integral (PI) controller. The DPC directly controls the Stator active and reactive powers, while the PI controllers is used to regulate the positive and negative sequence component. The proposed DPC-PI control strategy is verified by the simulation results during nonlinear loading. The models have been developed by means of MATLAB/SIMULINK software.
Abstract: The electrical power system is considered as the most complex man-made systems mainly due to their wide geographical coverage. Electrical energy industries contributes environmental pollution which rise questions concern environmental protection and methods of eliminating or reducing pollution from power plants either by design or by operational strategies. Electric power plants are mainly aimed to operate al low fuel cost strategies .In this paper a Multi –Objective Economic Emission Load Dispatch problem is solved to minimize the emission of nitrogen oxides (NOx) , oxides of other fuels that release during generation of electricity and fuel cost considering both Thermal generators and Wind turbines. A large number of iterations and oscillation are those of the major concern in solving the economic load dispatch problem by using the BFO(bacterial foraging optimization) method. By applying BFO method the economic dispatch problem is optimized to minimize the total generation cost of a power system while satisfying various equality and inequality constraints. The effect of Wind power on overall emission is also investigated here using Quadratic programming by wolf’s method. This method has better convergence characteristic. Wolf’s method is an extended simplex procedure which can be applied to Quadratic programming problems in which all the problem variables are non-negative.
Abstract: The Interline Power Flow Controller (IPFC) is a voltage-source-converter (VSC)-based flexible ac transmission system (FACTS) controller for series compensation in a multiline transmission system of a substation. The capability of injecting series voltages with controllable magnitude and phase angle makes it a powerful tool for better utilization of existing transmission lines in a multiline transmission system. IPFC is used to regulate active and reactive power flow in a multiline system, usually. In this paper, a control method for IPFC is proposed to control magnitude and phase angle of one sending bus of a substation. All degrees of freedom of IPFC and decoupled synchronous frame concept are used in the proposed control structure. Simulation results in Matlab/Simulink are presented to show the capability of IPFC in compensating the bus voltage.