The purpose of this paper is to provide a comprehensive presentation and interpretation of the Ensemble Kalman Filter (EnKF) and its numerical implementation. The EnKF has a large user group, and numerous publications have discussed applications and theoretical aspects of it. This paper reviews the important results from these studies and also presents new ideas and alternative interpretations which further explain the success of the EnKF. In addition to providing the theoretical framework needed for using the EnKF, there is also a focus on the algorithmic formulation and optimal numerical implementation. A program listing is given for some of the key subroutines. The paper also touches upon specific issues such as the use of nonlinear measurements, in situ profiles of temperature and salinity, and data which are available with high frequency in time. An ensemble based optimal interpolation (EnOI) scheme is presented as a cost-effective approach which may serve as an alternative to the EnKF in some applications. A fairly extensive discussion is devoted to the use of time correlated model errors and the estimation of model bias.

The Ensemble Kalman Filter: Theoretical formulation and practical implementation

http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

Energy is an essential ingredient of socio-economic development and economic growth. Renewable energy sources like wind energy is indigenous and can help in reducing the dependency on fossil fuels. Wind is the indirect form of solar energy and is always being replenished by the sun. Wind is caused by differential heating of the earth's surface by the sun. It has been estimated that roughly 10 million MW of energy are continuously available in the earth's wind. Wind energy provides a variable and environmental friendly option and national energy security at a time when decreasing global reserves of fossil fuels threatens the long-term sustainability of global economy. This paper reviews the wind resources assessment models, site selection models and aerodynamic models including wake effect. The different existing performance and reliability evaluation models, various problems related to wind turbine components (blade, gearbox, generator and transformer) and grid for wind energy system have been discussed. This paper also reviews different techniques and loads for design, control systems and economics of wind energy conversion system.

A review of wind energy technologies

1. Health care is a human right. 2. The care of the individual is at the center of health care, but the whole system needs to work to improve the health of populations. 3. The health care system must treat illness, alleviate suffering and disability, and promote health. 4. Cooperation with each other, those served, and those in other sectors is essential for all who work in health care. 5. All who provide health care must work to improve it. 6. Do no harm.

https://www.journalacs.org/article/S1072-7515(00)00768-7/pdf

Is this a practical approach

Induction generators are increasingly being used in nonconventional energy systems such as wind, micro/mini hydro, etc. The advantages of using an induction generator instead of a synchronous generator are well known. Some of them are reduced unit cost and size, ruggedness, brushless (in squirrel cage construction), absence of separate dc source, ease of maintenance, self-protection against severe overloads and short circuits, etc. In isolated systems, squirrel cage induction generators with capacitor excitation, known as self-excited induction generators (SEIGs), are very popular. This paper presents an exhaustive survey of the literature over the past 25 years discussing the process of self-excitation and voltage buildup, modeling, steady-state, and transient analysis, reactive power control methods, and parallel operation of SEIG.

Three-phase self-excited induction generators: an overview

Flood forecasting (FF) is one the most challenging and difficult problems in hydrology. However, it is also one of the most important problems in hydrology due to its critical contribution in reduc...

A Brief review of flood forecasting techniques and their applications

Self-excited induction generators (SEIGs) are increasingly being used in small-capacity isolated applications for harnessing both conventional and renewable energy resources. These SEIGs suffer from poor voltage regulation even when driven by constant speed prime movers or fixed head hydro turbines. The suitability of these SEIGs to regulate the terminal voltage is a key factor in deciding its use in various applications. This paper deals with the voltage-regulating (VR) schemes for SEIGs, which are found scattered in the literature, and summarizes their operational aspects and relative suitability. These VR schemes are classified on the basis of shunt and series compensation as classical schemes, schemes based on solid-state switching devices, and schemes based on self-commutating solid-state switching device converters. The recommendations drawn from this study are helpful in developing a new cost-effective regulating scheme of SEIGs for different industrial applications.

A Prospective on Voltage Regulation of Self-Excited Induction Generators for Industry Applications

A generalised dynamic model of a delta-connected three-phase self-excited induction generator (SEIG) has been developed using d-q variables in a stationary reference frame This model can handle symmetrical and unsymmetrical load and capacitor configurations, however, the SEIG performance during balanced and unbalanced faults has been studied, which include cases of extreme unbalance operation SEIG behaviour has been investigated considering the effects of main and cross flux saturation for load perturbation, three-phase and line-to-line short circuit, opening of one capacitor, two capacitors and a single line at the capacitor bank, opening of single-phase load, two-phase load, and a single line at load Simulated results are compared with experimental results and a close match between them validates the developed model

Transient performance of three-phase self-excited induction generator during balanced and unbalanced faults

/pdf/comparative-analysis-of-fuzzy-power-system-stabilizer-using-4gym6kw032.pdf

Comparative Analysis of Fuzzy Power System Stabilizer Using Different Membership Functions

The configuration of short-shunt self-excited induction generator feeding induction motor loads (SEIG-IM) suffers from excessive transients during startup of motor load under no load and unstable operation. These problems may be due to subsynchronous resonance as obtained with series compensated transmission line or due to the connected load system. The use of damping resistors across series capacitors is proposed to damp out the starting transients and for the stable operation. The steady-state model of short shunt SEIG-IM with damping resistors and resistive and motor load is developed to obtain the values of shunt and series capacitances for optimum voltage regulation. The simulated annealing like approach is used to solve voltage regulation optimization problem. The values of shunt and series capacitances and damping resistance are obtained for optimum voltage regulation under entire loading range and stable operation during starting and loading. The results are experimentally verified, which establish the effectiveness of damping resistance and developed algorithm.

Sanjay K. Jain

Papers

A Brief review of flood forecasting techniques and their applications

A Prospective on Voltage Regulation of Self-Excited Induction Generators for Industry Applications

Transient performance of three-phase self-excited induction generator during balanced and unbalanced faults

Comparative Analysis of Fuzzy Power System Stabilizer Using Different Membership Functions

Voltage regulation optimization of compensated self-excited induction generator with dynamic load