K. Shanti Swarup

Bio: K. Shanti Swarup is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Smart grid & Relay. The author has an hindex of 13, co-authored 77 publications receiving 677 citations.

Optimal relay coordination for microgrids using hybrid modified particle swarm optimization — Interval linear programming approach

Abstract: In practical power systems, the fault current sensed by the relay depends on location of the fault and network topological changes. Fault current sensed by the relay for near end fault is greater than that for a far end fault. In meshed distribution systems with Distribution Generation (DG), the fault currents are fed from both ends of the line and consequently the currents sensed by the relays at both ends are different. These variable fault currents may lead to miscoordination of directional overcurrent relays (DOCRs). To overcome this problem, the coordination constraints corresponding to the fault currents at different fault locations should be satisfied. This paper proposes a new approach based on Interval Linear Programming (ILP) which is hybridized with Modified Particle Swarm Optimization (MPSO). The basic idea is to convert the inequality constraints of a standard linear programming (LP) problem to interval constraints using theory of ILP and represent the ILP problem as a standard LP problem. This procedure reduces considerable number of coordination constraints and better sub-optimal solution is obtained compared to conventional optimization. The proposed method is tested on IEEE 14 bus test system in microgrid perspective.

Islanding detection using mathematical morphology for distributed generation

Abstract: The paper presents a novel method for islanding detection based on time domain, non linear signal processing tool called Mathematical Morphology. The method uses Multi-resolution morphological gradient (MMG) algorithm to operate on three phase voltages and currents at target DG location. The result of MMG algorithm is used to compute norm of the three phase voltage and current. The ratio of these norms (voltage and current) are used to obtain a norm ratio index for each phase. Norm index for Islanding detection is obtained by summing the norm ratio index of each of the three phases. Norm index is found to be very effective in detecting island in distribution system with distributed generation integration.

A new performance index for evaluating community virtual power plant with domestic storage

Abstract: Energy storage is a key component of the smart grid as it can be used to provide both peak and off-peak services to the grid, frequency regulation service, smoothen peak and trough of renewable generation, etc. In such a system, prosumers with embedded battery energy storage can be aggregated into a local community virtual power plant (VPP). Whilst many papers have been presented showing how virtual power plants could operate, it has been difficult to evaluate and compare their performance with respect to the grid requirements. In this paper, we present a methodology for evaluating VPP performance, and propose a novel performance index called the “Cumulative Performance Index” CPI, that can be used to evaluate VPPs under various scenarios. The CPI is derived based on grid requirements and VPP operation. In this paper we demonstrate the use of CPI to evaluate the optimization of a VPP under a pricing scheme using different initial battery conditions. The results shows how best grid operation does not necessarily match best prosumer or VPP operator benefit.

Power system restoration in smart grid environment

Abstract: This paper reviews the work done in power system restoration and its procedural development throughout the years. The issues during restoration are discussed in details. Network reconfiguration is done to minimize the losses of the line with minimal changes to the present network. Voltage profile is also a major issue during network reconfiguration which is also addressed in this reconfiguration process. The island formation during the restoration process and its issues are discussed in this paper. A suitable method for island formation during system restoration is proposed.

Graph theory based corrective control strategy during single line contingency

Abstract: This paper presents a new Graph Theory based corrective control strategy to alleviate overloads of transmission lines, with the help of a local optimization concept. A Direct Acyclic Graph (DAG) technique for selection of participating generators and load buses with respect to a contingency is presented. Particle Swarm Optimization (PSO) technique has been employed for generator rescheduling and/or load shedding to the identified generators and loads, to bring back the system from abnormal to normal operating state. The effectiveness of the proposed approach is demonstrated for different contingency cases in IEEE 57 and modified IEEE 118 bus systems. The result shows that the proposed approach is computationally fast, reliable and efficient, in restoring the system to normal state after a contingency with minimal control actions.

Online Short-term Solar Power Forecasting

Abstract: This paper describes a new approach to online forecasting of power production from PV systems. The method is suited to online forecasting in many applications and in this paper it is used to predict hourly values of solar power for horizons of up to 36 h. The data used is 15-min observations of solar power from 21 PV systems located on rooftops in a small village in Denmark. The suggested method is a two-stage method where first a statistical normalization of the solar power is obtained using a clear sky model. The clear sky model is found using statistical smoothing techniques. Then forecasts of the normalized solar power are calculated using adaptive linear time series models. Both autoregressive (AR) and AR with exogenous input (ARX) models are evaluated, where the latter takes numerical weather predictions (NWPs) as input. The results indicate that for forecasts up to 2 h ahead the most important input is the available observations of solar power, while for longer horizons NWPs are the most important input. A root mean square error improvement of around 35% is achieved by the ARX model compared to a proposed reference model.

Particle Swarm Optimization: Technique, System and Challenges

Abstract: Particle Swarm Optimization (PSO) is a biologically inspired computational search and optimization method developed in 1995 by Eberhart and Kennedy based on the social behaviors of birds flocking or fish schooling. A number of basic variations have been developed due to improve speed of convergence and quality of solution found by the PSO. On the other hand, basic PSO is more appropriate to process static, simple optimization problem. Modification PSO is developed for solving the basic PSO problem. The observation and review 46 related studies in the period between 2002 and 2010 focusing on function of PSO, advantages and disadvantages of PSO, the basic variant of PSO, Modification of PSO and applications that have implemented using PSO. The application can show which one the modified or variant PSO that haven’t been made and which one the modified or variant PSO that will be developed.

Synchrophasor Measurement Technology in Power Systems: Panorama and State-of-the-Art

Abstract: Phasor measurement units (PMUs) are rapidly being deployed in electric power networks across the globe. Wide-area measurement system (WAMS), which builds upon PMUs and fast communication links, is consequently emerging as an advanced monitoring and control infrastructure. Rapid adaptation of such devices and technologies has led the researchers to investigate multitude of challenges and pursue opportunities in synchrophasor measurement technology, PMU structural design, PMU placement, miscellaneous applications of PMU from local perspectives, and various WAMS functionalities from the system perspective. Relevant research articles appeared in the IEEE and IET publications from 1983 through 2014 are rigorously surveyed in this paper to represent a panorama of research progress lines. This bibliography will aid academic researchers and practicing engineers in adopting appropriate topics and will stimulate utilities toward development and implementation of software packages.