Thyristor-Based FACTS Controllers for Electrical Transmission Systems

In this paper, a real-time implementation of selective harmonic elimination pulsewidth modulation (SHEPWM) using generalized Hopfield neural network (GHNN) as applied to the single-phase inverter is designed and discussed. Finding the location of the switching instants in the case of SHEPWM involves the solution of a set of nonlinear algebraic transcendental equations. The problem is redrafted as an optimization problem, and it is solved by using GHNN. Though, in principle, the $n$ number of harmonics can be eliminated using the presented methodology, this paper tries for the case of the elimination of the 5th-, 7th-, 11th-, and 13th-order harmonics while retaining the desired fundamental. An energy function is formulated for this problem and the set of ordinary differential equations (ODEs) describing the behavior of GHNN is obtained. A program in KEIL C was developed to solve these systems of ODEs by the Runge–Kutta fourth-order method to give the switching instants for continuously varying modulation indexes $(M)$ . A MATLAB simulation was carried out, and an experimental setup was also constructed in order to validate the simulated results. The fast Fourier transform analysis of the simulated output voltage waveform and the experimental output voltage waveform confirms the effectiveness of the proposed method. Hence, the proposed method proves that it is much applicable in the industrial applications by virtue of its suitability in real-time applications.

Design and Real-Time Implementation of SHEPWM in Single-Phase Inverter Using Generalized Hopfield Neural Network

Wind turbine blade geometry design based on multi-objective optimization using metaheuristics

This paper presents a method to solve Static Economic dispatch incorporating solar energy using Dragonfly algorithm. Economic dispatch is carried out considering valve point loading and prohibited operating zone constraints. Solar energy system is modelled using Beta distribution function and included in the objective function. The output power of solar farm is forecasted for four seasons. Different loading conditions are assumed in various seasons for the detailed analysis. Dragonfly algorithm, an emerging optimization technique for constrained optimization problems is applied as the optimization tool here. The proposed method is validated in 6 generator, 15 generator and 17 generator practical south Indian test systems. The results are compared with the state of art heuristic optimization method available in the literature.

Generation dispatch of combined solar thermal systems using dragonfly algorithm

Multi-period wind integrated optimal dispatch using series PSO-DE with time-varying Gaussian membership function based fuzzy selection

Design of economic dispatch model for Gencos with thermal and wind powered generators

From the viewpoint of operational planning, this paper focuses on the evaluation of the impact of FACTS devices on control of voltage profile and line flows. This paper presents modeling and interfacing techniques of static VAr compensator (SVC) and thyristor controlled series capacitor (TCSC) for real time long term simulation. The proposed models are shown to be effective both for maintaining the voltage at load bus and real power flow through a typically selected line. The effectiveness of the controls are demonstrated for a standard nine bus system

Modeling of SVC and TCSC for power system dynamic simulation

This paper proposes a Technical and Cost-Effective Analysis of Hybrid Renewable Energy System (HRES) in Metropolitan Cities in India using a Hybrid Optimisation Model for Electric Renewable (HOMER)...

Techno-economic study of hybrid renewable energy system of Metropolitan Cities in India

Thisreview focuses on inverter topologies for Photo Voltaic (PV) modules., which are connected with single phase grid systems. Various inverter topologies for PV modules such as (i) Centralized inverter (ii) String inverter (iii) Multi-string inverter and their recommended standards., trends., Principle of integration issues connecting with grid systems are presented in this review. The centralized and string PV systems have drawbacks such as losses due to mismatching of PV module., high voltage DC cables between PV modules and the inverter., limited power rating of converter unit and additional power losses due to the string diodes. The solutions for the above stated problems are overcome by multi string inverter. The different Pulse Width Modulation (PWM) technique for PV inverter modules is being presented in this review.

A survey of single phase grid connected photovoltaic system

Programmed PWM technique requires solution of set of non-linear transcendental equations in order to obtain the switching angles as well as for controlling the fundamental component of inverter output voltage. This paper presents a new method to determine the optimum switching angles for Selective Harmonic Eliminated PWM (SHEPWM) inverter. The complete solutions for unipolar SHEPWM switching pattern which produce the fundamental while not generating specifically chosen harmonics are investigated. The estimated angles are applied to an inverter circuit in order to verify its validity through output waveforms, THD and FFT. Since the THD is high due to low number of harmonic orders are eliminated, a low pass filter is also designed in order to filter the unwanted harmonics.

K. Keerthivasan

Papers

Design of economic dispatch model for Gencos with thermal and wind powered generators

Modeling of SVC and TCSC for power system dynamic simulation

Techno-economic study of hybrid renewable energy system of Metropolitan Cities in India

A survey of single phase grid connected photovoltaic system

Estimation of optimal single phase inverter's switching angles using Pattern Search Method