T. S. Bhatti

Bibliography on the application of induction generators in nonconventional energy systems

Induction generators are increasingly being used in nonconventional energy systems such as wind, mini/micro-hydro, biogas, etc. The advantages of using an induction generator instead of synchronous generator are well known. Some of them are reduced unit cost and size, ruggedness, absence of separate DC source, ease of maintenance, self-protection against severe overloads and short circuits, etc. An attempt is made in this paper to present an exhaustive bibliography on the application of induction generators in nonconventional energy systems.

Automatic Generation Control in an Interconnected Power System Incorporating Diverse Source Power Plants Using Bacteria Foraging Optimization Technique

Abstract This article presents automatic generation control (AGC) of a two-area interconnected power system with diverse energy sources using the bacteria foraging optimization technique. The control areas of interconnected power systems consist of hydro, thermal, and gas power plants. In this study, the proportional-integral-derivative (PID) structures of AGC regulators are designed for various case studies identified herein. An artificial intelligent optimization algorithm using the modeling behavior of E. Coli bacteria present in human intestines, is applied to tune the gains of PID structured AGC regulators. The closed-loop system dynamic response plots are obtained with designed AGC regulators for various power system models. The effectiveness of the proposed AGC regulators is demonstrated in the wake of a 1% step load disturbance in one of the control areas. It has been shown that the system dynamic responses subject to a step load disturbance are superior over other power plant combinations in a control area with only thermal and gas power plants participating in the AGC schemes, and it is sluggish/poor when only hydro power plants participated in the AGC scheme as one of the diverse sources in the power system.

Automatic reactive power control of wind-diesel-micro-hydro autonomous hybrid power systems using ANN tuned static VAr compensator

This paper presents an artificial neural network (ANN) based approach to tune the parameters of the SVC reactive power controller over a wide range of typical load model parameters. The multi-layer feed-forward ANN with the error back-propagation training is employed to tune the static VAr compensator (SVC) controller for controlling the reactive power of variable slip/speed isolated wind-diesel-micro-hydro hybrid power systems. Transient responses of sample hybrid power system have been presented.

Sampled-data Automatic Load Frequency Control of a Single Area Power System with Multi-source Power Generation

Abstract In this article, discrete-mode automatic load frequency control (ALFC) of a more realistic single area power system with multi-source power generation is studied. The system transfer function model comprises hydro, thermal and gas generations with speed governor models and system load for studying the dynamic performance for small load disturbances. A proportional plus integral (PI) load frequency control scheme is applied only to thermal and gas power generations, and hydro is allowed to operate at its scheduled generation level with only speed governor control. Genetic algorithm (GA) is used to obtain the optimal gains of the conventional discrete data proportional-integral controller. Integral squared error (ISE) and integral time absolute error (ITAE) performance indices are used to obtain optimal discrete ALFC parameters. The effects on transient performance of the system are investigated for common and individual ALFC controller gains of thermal and gas power generations. The effect of sampling period of the controller signal on the performance of the continuous system is also investigated. Finally, transient responses are shown for different scheduled loading conditions.

Load Frequency Control of an Isolated Small Hydro Power Plant Using Multi-pipe Scheme

Abstract In this article, a load frequency control technique for an isolated small hydro power plant based on a multiple flow control system is proposed. In general, the frequency of the system is controlled by employing a dump load whose rating is equal to the rated power output of the plant. The proposed scheme reduces the size of the dump load to 50%, as 50% input power of the hydro plant is controlled by an on/off control. A generalized transfer function model for the system is developed with on/off control logic, and the parameters were optimized using the integral time absolute error technique. The on/off control linearly raises or lowers the generation. Finally, transient responses are shown for low, medium, and high head installations with different loading conditions.

Reactive power control of wind-diesel-micro-hydro hybrid power systems using matlab/simulink

This paper presents reactive power control of isolated wind-diesel-micro-hydro hybrid power system for realistic load disturbance using matlab/simulink. The mathematical model of the system based on matlab/simulink is developed. Reactive power control performance is compared using three different types of Static VAR Compensators (SVC). Transient responses for step plus normally distributed or band limited white noise random change in load have also been presented in this paper.

Closure on "Bibliography on the application of induction generators in nonconventional energy systems"

For original paper see Bansal et al. (IEEE Trans. Energy Conversion, vol.18, p.433-9, September 2003). The present authors reply to a comment by Mathur (IEEE Trans. Energy Conversion, vol.19, no.3, p.650, September 2004).

Study the effect of system parameters on controller gains for discrete AGC of hydro-thermal system

This paper investigates the effect of system parameters on optimum controller gains for discrete data automatic generation control of an interconnected power system. The optimum gains of the system have been analyzed for different values of sampling periods in discrete mode of operation. The effect of different loading conditions on the optimum gains is also investigated. As we know that load varies widely throughout the day. The optimum gains calculated for the nominal loading may not be optimum at other loading condition. Therefore the system has been analyzed for different loading conditions. The load variation of 30-100% has been considered for the investigation. This paper also deals with the proper selection of speed regulation parameter R for the design of speed governor. The hydro-thermal system has been taken for investigation. The dynamic responses are obtained for 1% load perturbation in thermal area system. The Matlab/simulink software is used for the simulation work.

An Optimization Algorithm for Unit Commitment Economic Emission Dispatch Problem

The emission rate of greenhouse gases results in global warming and having some other environment-related issues and uncertainties. This work presents a new approach to handle the effect of uncertainties and economic generation. An optimization technique Lagrangian relaxation with priority list (LR-PL) has been used to handle Unit Commitment and Economic Emission Dispatch (UCEED) problem with the inclusion of renewable energy source such as solar energy. An optimization technique has been developed to determine optimal solution and verified. The proposed approach has been applied at standard IEEE 69-bus 11 electrical generators system. An integration of the generator units with solar system is implemented. After integration with solar system, two cases of peak and off-peak hours have been studied. It is found that the developed approach is capable of handling the uncertainties in the solar radiation in an efficient manner. The compared results show the better performance of the developed approach over the existing ones. The compared results show the effectiveness of the developed approach.

Stability Study of Integrated Microgrid System

India has a high potential of renewable energy and the electrical power produced from these sources can be utilized for various applications. One of the application is that these sources can be clustered to form a micro grid for improving the availability of power supply especially in rural areas. In this paper, an attempt has been made to study and model renewable sources based micro grid having limited grid support. Renewable sources considered while modeling are Photo Voltaic system (PVS), Wind Energy Conversion System (WECS) and Biogas-genset. Grid provides constant power to the system (Limited grid) which is having power from the renewable sources to ensure continuity of the power supply. A STATCOM has been introduced for the reactive power support of the micro grid. Stability study has been performed to validate the results.