Sheeraz Kirmani

Empirical correlation of estimating global solar radiation using meteorological parameters

An empirical model for the estimation of solar energy on the basis of Angstroms model is proposed in this work. Seven regression equations are developed by using different meteorological parameters such as mean sunshine duration per hour, temperature, relative humidity, wind speed, and rainfall. The performance of the model is determined on the basis of statistical indicators like correlation coefficient(r), coefficient of determination (R2), root mean square error (RMSE), mean percentage error (MPE), and mean bias error (MBE). The results show that the equation with the highest value of r, R2 and the least value of RMSE, MPE, and MBE provides better results.

Optimal placement of SPV based DG system for loss reduction in radial distribution network using heuristic search strategies

The appropriate location of distributed generation (DG) is very important for loss reduction in a radial distribution system. In this paper a methodology for determining the optimum size and location for installing the solar photovoltaic (SPV) based DG system for supplying the active power at the node in a radial distribution system for loss reduction is presented. The objective of this paper is to apply heuristic search strategies to determine the node for the appropriate placement of DG. In heuristic approach, a critical node, called sensitive node is selected based upon maximum power losses caused for installing DG system. This method ensures that voltage constraints are met. This heuristic approach is useful for large distribution system and can be useful for online implementation. Test results have been tested on IEEE-33 bus system and presented.

Techno-economic viability of three different energy-supplying options for remote area electrification in India

Distributed power generation based on renewable energy sources brings new life and hope to electrify remote villagers. The proposed work suggests the techno-economic feasibility of three different energy-supplying alternatives namely the solar photovoltaic (SPV) system, diesel generator system and extending the grid connection for energy supply to a remote village located around 15 km away from the place where grid supply is available. Design of all the above three systems along with their economic analysis is carried out in this paper. A comparison on the basis of economic indicators like unit cost of electricity, net present value and payback period among the three systems is also discussed. The results show that the SPV system is economically more viable among the three options apart from environment benefits. This study may provide a new direction for energy planners to supply energy in remote non-electrified areas of India through SPV systems.

Optimal allocation of SPV based DG system for loss reduction and voltage improvement in radial distribution systems using approximate reasoning

Optimal siting and siting of distributed generation (DG) is a key for loss minimization and improvement of voltage profile in distribution systems. The present paper proposes a methodology for optimal siting and sizing of solar photovoltaic (SPV) based DG system in radial distribution systems, so that the electrical power losses in the system can be minimized while maintaining the voltage profile in the system within the specified limits. The SPV based DG system supplies the active power in the distribution system at the node where it installed because most of the invertors used for grid interfacing of SPV based systems are current source invertors. The losses and voltage profile in the system is evaluated using a load flow program. Voltage along with active power loss reduction index of each node is fed into fuzzy expert system (FES) whose output is DG placement suitability. DG is then placed at the node with the highest suitability provided voltage constraints are not violated. Exact loss formulae is then used to determine the size of the DG to be placed at the incoming node which was found using FES.

Performance enhancement methodologies for grid connected photovoltaic systems

The inherent intermittent nature of renewable energy resources introduces the great challenges to integrate their generation to the utility grid. The rapid increase in grid-connected photovoltaic systems and their intermittent nature of generation introducing many issues like voltage fluctuations, harmonic distortions for sustainable power generation. This paper presents modeling, simulation and performance enhancement methodologies for grid-connected PV system with implementing suitable MPPT topology and control algorithm for battery energy storage system (BESS). BESS provide benefits to mitigate power fluctuation and regulating DC-link voltage and MPPT topology based on incremental conductance with integral regulator provides accurate and fast tracking efficiency to extract maximum possible power from PV array systems and make the PV grid connected generation systems more reliable. The effectiveness of proposed control strategies for performance enhancement of grid connected PV systems is evaluated using MATLAB/SIMULINK environment.

Development of Effective Technique for Integration of Hybrid Energy System to Microgrid

Due to lack of energy resources, renewable energy sources have increased fabulous consideration and settled rapidly in recent years. It is a very decisive issue to integrate hybrid energy system to the microgrid. In this paper, a control model for integration of hybrid energy sources to the microgrid and the effectiveness of the control algorithm for DC/DC converter under variation of different load demands are presented. A nearly constant dc voltage at the output of hybrid energy system is preferred for high efficiency So, there is a necessity for developing control techniques for a grid integration hybrid system including a method for output voltage control that stabilizes the voltage and dc-link capacitance. The simulation results of MATLAB/SIMULINK model report that the proposed control algorithm has a good performance. Therefore an idea of an effective technique for integration of solar/wind system to microgrid has been given.

Implementation of genetic algorithm to find the optimal timing of overcurrent relays

This paper discusses a new approach to optimize overcurrent relay coordination in power distribution system by using a genetic algorithm. A modified objective function with constraints is taken to solve the relay coordination problem considering time setting and current setting multiplier. The result shows that the proposed method is fast, accurate and applicable compared to previous work proposed. In this study IEEE-8 bus system is tested to demonstrate the coordination and confirm that proposed approach method is practical.