M.S. Sachdev

Bio: M.S. Sachdev is an academic researcher from University of Saskatchewan. The author has contributed to research in topics: Power-system protection & Protective relay. The author has an hindex of 27, co-authored 92 publications receiving 3531 citations. Previous affiliations of M.S. Sachdev include University of Waterloo.

An on-line relay coordination algorithm for adaptive protection using linear programming technique

Abstract: An adaptive system for protecting a distribution network should determine and implement relay settings that are most appropriate for the prevailing state of the power system. This paper presents a technique for determining coordinated relay settings. The technique uses the Simplex two-phase method; Phase I determines whether the constraints selected for illustrating the conditionality between primary and back up relays are feasible, and Phase II finds the optimal relay settings. A looped distribution system, protected by directional overcurrent relays, was used for testing the technique. The tests were conducted in a laboratory environment; some results from those tests are reported in the paper.

A Least Error Squares Technique For Determining Power System Frequency

Abstract: An algorithm for measuring frequency at a power system bus is presented in this paper. The algorithm is based am the least error squares curve fitting technique and uses digitized samples of voltage at a relay locaticn. Mathematical developnent of the algorithm is presented and the effects of key parameters, that affect the performance of the algorithm, are discussed. The algorithm was tested using simulated data and data recorded fran a dynamic frequency source. Results of sample tests are also presented in this paper.

A technique for estimating transmission line fault locations from digital impedance relay measurements

Abstract: A technique is presented that is suitable for estimating locations of shunt faults. The estimates are reasonably accurate even if the fault resistance is substantial and the transmission line is connected to energy sources at both terminals. The technique uses post fault fundamental-frequency voltages and currents measured at the two line terminals. The measurements need not be synchronized, and the source impedances are not used by the estimation procedure. The mathematical development of the technique is presented. Sample test results using simulated fault data are included. >

IEEE standard inverse-time characteristic equations for overcurrent relays

Abstract: This paper introduces the new standard "IEEE standard inverse-time characteristic equations for overcurrent relays". It provides an analytic representation of typical electromechanical relays operating characteristic curve shapes in order to facilitate coordination when using microprocessor-type relays.

Design, implementation and testing of an artificial neural network based fault direction discriminator for protecting transmission lines

Abstract: This paper describes a fault direction discriminator that uses an artificial neural network (ANN) for protecting transmission lines. The discriminator uses various attributes to reach a decision and tends to emulate the conventional pattern classification problem. An equation of the boundary describing the classification is embedded in the multilayer feedforward neural network (MFNN) by training through the use of an appropriate learning algorithm and suitable training data. The discriminator uses instantaneous values of the line voltages and line currents to make decisions. Results showing the performance of the ANN-based discriminator are presented in the paper and indicate that it is fast, robust and accurate. It is suitable for realizing an ultrafast directional comparison protection of transmission lines. >

Particle Swarm Optimization: Basic Concepts, Variants and Applications in Power Systems

Abstract: Many areas in power systems require solving one or more nonlinear optimization problems. While analytical methods might suffer from slow convergence and the curse of dimensionality, heuristics-based swarm intelligence can be an efficient alternative. Particle swarm optimization (PSO), part of the swarm intelligence family, is known to effectively solve large-scale nonlinear optimization problems. This paper presents a detailed overview of the basic concepts of PSO and its variants. Also, it provides a comprehensive survey on the power system applications that have benefited from the powerful nature of PSO as an optimization technique. For each application, technical details that are required for applying PSO, such as its type, particle formulation (solution representation), and the most efficient fitness functions are also discussed.

Synchronized Phasor Measurements and Their Applications

Abstract: Phasor Measurement Techniques.- Phasor Estimation of Nominal Frequency Inputs.- Phasor Estimation at Off-Nominal Frequency Inputs.- Frequency Estimation.- Phasor Measurement Units and Phasor Data Concentrators.- Transient Response of Phasor Measurement Units.- Phasor Measurement Applications.- State Estimation.- Control with Phasor Feedback.- Protection Systems with Phasor Inputs.- Electromechanical Wave Propagation.

Energy function analysis for power system stability

Abstract: (1990). ENERGY FUNCTION ANALYSIS FOR POWER SYSTEM STABILITY. Electric Machines & Power Systems: Vol. 18, No. 2, pp. 209-210.

Computer Relaying for Power Systems

Abstract: This text/reference presents a comprehensive, up-to-date account of computer relaying in power systems, based in part on the author's extensive experience in the field. Provides background material on current relaying practices, and covers the mathematical foundations for relaying algorithms. Each chapter contains helpful illustrations, examples, and problems.

Frequency tracking in power networks in the presence of harmonics

Abstract: Three new techniques for frequency measurement are proposed. The first is a modified zero-crossing method using curve fitting of voltage samples. The second method is based on polynomial fitting of the discrete Fourier transform (DFT) quasi-stationary phasor data for calculation of the rate of change of the positive sequence phase angle. The third method operates on a complex signal obtained by the standard technique of quadrature demodulation. All three methods are characterized by immunity to reasonable amounts of noise and harmonics in power systems. The performance of the proposed techniques is illustrated for several scenarios by computer simulation. >