Papers by ABHIJIT CHAKRABARTI
International Journal of Electrical Power & Energy Systems, 2011
Grid connected EHV transformers experience various terminal disturbances when in service. The pre... more Grid connected EHV transformers experience various terminal disturbances when in service. The present work attempts to investigate the voltage stresses that may develop on the transformer insulations under a variety of terminal disturbances. A number of standard and non-standard wave shapes like lightning impulse, chopped lightning impulse, steep-front long tail switching surge and oscillatory transient over voltages have been simulated and impressed on the terminals of a 400 kV EHV power transformer operating in the Indian power grid to ascertain how the winding insulations are stressed under these disturbances. Relevant section of the Indian power grid and the transformer has been modeled using Alternative Transient Program (ATP). It has been established that oscillatory system transients can trigger natural resonate frequencies of the transformers causing high voltage stresses on the insulations. Short Time Fourier Transform (STFT) analysis of the oscillatory voltage response of the windings confirmed the presence of resonant frequencies indicating forced resonance. Some remedial measures involving winding design modifications have been suggested in the paper to overcome the problem.
Fundamental Models of Synchronous Machine
Power System Small Signal Stability Analysis and Control, 2014
A brief overview of synchronous machine and its principle of operation have been presented in thi... more A brief overview of synchronous machine and its principle of operation have been presented in this chapter. Dynamic model of synchronous machine in a–b–c reference frame has been discussed. The theory of Park's transformation and conversion from a–b–c reference frame to d–q–o reference frame has been explained. The concept and physical interpretations of per unit (pu) representation and scaling of synchronous machine dynamic equations are presented. Rotor dynamic equations and stator algebraic equations in terms of flux–current relationship with equivalent circuit representations are discussed. Modeling of different elements of synchronous machine excitation system and state space model of IEEE Type I excitation system has been furnished in detail.
Response of EHV Grid Transformers to System-Originated Oscillatory Switching Transients
IEEE Transactions on Power Delivery, 2012
This paper investigates the conditions for transformer winding resonances with an emphasis on osc... more This paper investigates the conditions for transformer winding resonances with an emphasis on oscillatory excitation voltages originating from various switching events in the power grids. A section of the Eastern Regional Power Grid in India has been simulated in this paper by using the Alternative Transient Program for the purpose of defining high-frequency transient voltages which may occur during various
IEEE Transactions on Power Delivery, 2006
This investigation aims to develop a comprehensive microcomputer based fault protection scheme fo... more This investigation aims to develop a comprehensive microcomputer based fault protection scheme for indicating various types of faults in a radial transformer feeder in subtransmission or distribution circuits and its protection against those faults. The type of fault in the feeder can also be determined by observing the phase angles of the primary currents of the transformer with which the feeder is connected at its secondary. This method dispenses off conventional electromagnetic relays and HRC fuses in feeder protection schemes. The developed system provides necessary information regarding the faulted phase and displays appropriate symbols on the display screen of the microcomputer about the type of fault.
With deregulation and open access of the electricity supply industry occurring internationally, t... more With deregulation and open access of the electricity supply industry occurring internationally, there is an increasing need to develop power market oriented optimal power flow (OPF) algorithm for power systems of developing countries. A genetic algorithm based OPF is proposed for this purpose, which inherits both the real and reactive power constraints with loss expressions involving B-coefficients for active power and C-coefficients for reactive power. The significance of the paper is the development of a flexible OPF methodology using both real and reactive power constraints, which can address a very important issue like determination of the spot price for each participant generator in the economic operation of restructured power systems in the developing countries. The proposed methodology has been tested in a 203 buses 267 lines 23 machines real power system of eastern part of India and the simulation results have established that the proposed method is promising for large scale optimizations under deregulated environments.
An evolutionary algorithm for consumer welfare optimisation of a contingent power network
2011 IEEE Recent Advances in Intelligent Computational Systems, 2011
Page 1. An Evolutionary Algorithm for Consumer Welfare Optimisation of a Contingent Power Network... more Page 1. An Evolutionary Algorithm for Consumer Welfare Optimisation of a Contingent Power Network Sawan Sen1 Sandip Chanda2 Electrical Engineering Department Techno India EM 4/1 Sector V, Salt Lake, Kolkata, India ...
Genetic algorithm based spot pricing of electricity in deregulated environment for consumer welfare
International Conference on Electrical & Computer Engineering (ICECE 2010), 2010
Abstract This paper proposes a systematic method for evaluation of optimal spot prices using gene... more Abstract This paper proposes a systematic method for evaluation of optimal spot prices using genetic algorithm as well as classical method. Spot pricing of electricity in a power system was proposed during early eighties considering unit generation and consumer ...
With deregulation and open access of the electricity supply industry occurring internationally, t... more With deregulation and open access of the electricity supply industry occurring internationally, there is an increasing need to develop power market oriented optimal power flow (OPF) algorithm for power systems of developing countries. A genetic algorithm based OPF is proposed for this purpose, which inherits both the real and reactive power constraints with loss expressions involving B-coefficients for active power and C-coefficients for reactive power. The significance of the paper is the development of a flexible OPF methodology using both real and reactive power constraints, which can address a very important issue like determination of the spot price for each participant generator in the economic operation of restructured power systems in the developing countries. The proposed methodology has been tested in a 203 buses 267 lines 23 machines real power system of eastern part of India and the simulation results have established that the proposed method is promising for large scale...
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Papers by ABHIJIT CHAKRABARTI