Dheeraj Kumar Khatod

Evolutionary programming based optimal placement of renewable distributed generators

An evolutionary programming (EP) based technique has been presented for the optimal placement of distributed generation (DG) units energized by renewable energy resources (wind and solar) in a radial distribution system. The correlation between load and renewable resources has been nullified by dividing the study period into several segments and treating each segment independently. To handle the uncertainties associated with load and renewable resources, probabilistic techniques have been used. Two operation strategies, namely “turning off wind turbine generator” and “clipping wind turbine generator output”, have also been adopted to restrict the wind power dispatch to a specified fraction of system load for system stability consideration. To reduce the search space and thereby to minimize the computational burden, a sensitivity analysis technique has been employed which gives a set of locations suitable for DG placement. For the proposed EP based approach, an index based scheme has also been developed to generate the population ensuring the feasibility of each individual and thus considerably reducing the computational time. The developed technique has been applied to a 12.66-kV, 69-bus distribution test system. The solutions result in significant loss reduction and voltage profile improvement.

Analytical Approach for Well-Being Assessment of Small Autonomous Power Systems With Solar and Wind Energy Sources

This paper presents a systematic analytical approach for the well-being assessment of small autonomous power systems (SAPSs) with wind and solar energy sources. The proposed technique accounts for the uncertainties associated with solar irradiance, wind speed, demand, and outages of various generating units. The impact of wind power fluctuation on the system stability is also assessed by limiting the wind power dispatch to a certain percentage of system load. Well-being assessment and production costing simulation for SAPS are performed using proposed analytical approach and Monte Carlo simulation (MCS) method, and then, obtained results are compared in terms of accuracy and computational time. The comparison shows that the developed technique requires less computational time than MCS method, with reasonable accuracy, and thus, validates the usefulness of proposed analytical method. The impact of renewable energy penetration on a SAPS is also analyzed using the proposed method.

A novel approach for sensitivity calculations in the radial distribution system

In this paper, a novel approach for calculating the sensitivities of active/reactive power loss and voltage magnitudes with respect to active/reactive power injection at any bus in the radial distribution system is presented. In a radial distribution system, the changes in bus voltages and branch flows due to active/reactive power injection at any bus depend on the network topology. The key to the present method is the formation of a matrix whose structure is dependent only on the network topology. The proposed method is able to calculate the various sensitivity indices for single as well as multiple sources in the system. It is also able to handle all possible radial distribution system structures regardless of the system size proficiently. The results obtained by the proposed method have been compared with the simulated (conventional load flow) and the adjoint network approach results

Optimized daily scheduling of wind-pumped hydro plants for a day-ahead electricity market system

This paper presents a new approach for optimal daily scheduling of hybrid wind-pump storage hydro (WPSH) facility owned by an independent power producer (IPP). WPSH system has been considered as a participant of a day-ahead electricity market and mathematical formulation has been developed accordingly. The aim of developed formulation is to maximize the profit to the WPSH owner. The usefulness of the developed mathematical formulation has been tested on a test system and the solution has been obtained by Linear Programming technique using Primal-Dual Interior-Point method.

Single-phase single-stage grid-interactive photovoltaic system with active filter functions

This paper deals with modeling, control and co-simulation of a single-phase single-stage Grid-interactive photovoltaic (PV) system with active filter functions. Single-phase PV systems are the most prevalent in roof-top configurations. In this paper, the modeling of a PV array with maximum power point tracking is performed in MATLAB/Simulink. The developed PV array model may be directly connected to dc-side of the voltage source inverter used for grid PV interaction in order to evaluate its performance. This paper also deals with the development of a controller which either controls PV power or works as an active power filter or performs both the functions simultaneously. The injected active and reactive powers are regulated by changing the phase and amplitude, respectively, of the inverter output voltage. The simulation model of the overall system is developed in MATLAB/Simulink environment and then co-simulated (real-time) in digital signal processor TMS320F2812 through processor in loop (PIL) under rapidly changing atmospheric and load conditions to confirm its effectiveness as well as robustness.

Sizing and siting of distributed generation in distribution networks for real power loss minimization using analytical approach

This paper presents a method based on analytical approach for real power loss minimization of distribution networks by injecting power by the Distributed Generation (DG) operating at a given power factors. This method does not require calculation of Zbus matrix, inverse of Ybus matrix or Jacobean matrix as well as requires less computation time. The proposed method is tested on an IEEE 33-bus radial distribution test system. The results obtained by this proposed method validate the suitability and importance of appropriate DG allocation in power distribution networks for the performance improvement.

An off-grid hybrid system scheduling for a remote area

With the advent of renewable technologies in the power market, it is of keen interest of researchers to utilize these technologies in the most optimum manner. The unit cost of energy particularly from solar energy is much higher when compared with conventional energy sources. Nowadays, the emphasis is on the integrated utilization of these resources to minimize the cost and maximize the profit. In this paper, an optimal daily scheduling approach for a solar-wind-diesel system with battery storage has been presented. A mathematical model has been developed with the objective of maximizing profit. The problem has been optimized using Linear Programming technique using Primal-Dual Interior Point Method. This model is then tested on a test system and in order to obtain results MATLAB codes have been developed.

Review of methods for optimal sizing and siting of Distributed Generation

The optimum installation and sizing of Distributed Generation (DG) aims to extract the maximum environmental, economical and technical benefits for customers as well as energy supply companies. The installation of DG would be maximum beneficial for the areas, where the central power generating units are not practical, or remote and small area where the installation of transmission lines are almost impossible, and also availability of unused land. The optimal installation of DG in distribution system provides the information about proper operation of distribution networks with the primary aims to minimization of the system losses, improvement of the voltage profile, reliability, enhance the system stability and loadability. Many techniques and models have been advised to achieve the above said objectives are reviewed in this paper.

Cost Analysis for Electromechanical Equipment in Small Hydropower Projects

Small hydropower (SHP) is one of the most favorable and environmentally benign energy technologies for generation of electrical power. For development of a SHP project, its technical feasibility and economical viability are considered as the foremost requirements. From cost point of view, the most important elements are the electromechanical equipment, since their cost shares a high percentage in the total cost of the project. In the present study, an attempt has been made to develop correlations for cost of the electromechanical equipment used in SHP projects considering head, installed capacity, and rating such as kilo volt amperes (kVA), power factor (pf), and turn ratio of transformer as cost-influencing parameters. The cost correlation has been developed for high head schemes with head ranging from 100 m to 500 m. To validate the analytical results, the cost of electromechanical equipment determined by the developed correlations is compared with the cost data collected for recently developed such projects. It has been found that the developed correlation for cost of electromechanical equipment may be used for cost estimation of future SHP projects with reasonable accuracy.

Distribution loss allocation technique with distributed generations

The cost of real power generation is affected by distribution losses which must be allocated fairly between generators and consumers to get the economic efficiency of the electricity market. The paper presents a new methodology for allocation of losses to network participants of radial distribution networks (RDNs) in the liberalized electricity market. The proposed method is based on the power summation algorithm. By using a circuit based branch oriented approach, it develops suitable relationship between branch losses and injected real and reactive power in the nodes. The proposed method develops new scheme for distributing cross terms by multiplicative of generator and load power which oppose the allocation techniques as described in the literature. Application of the proposed method for loss allocation is illustrated on 33-node RDNs incorporating three distributed generations. In order to validate the proposed method and show its effectiveness, it has been compared with other method.