Authors: Shashwati Ray; Shimpy Ralhan
Addresses: Department of Electrical Engineering, Bhilai Institute of Technology, Durg (C.G.), India ' Department Electrical and Electronics Engineering, Shri Shankaracharya Group of Institutions, Bhilai (C.G.) India
Abstract: This paper addresses the problem of uncertainties in the input parameters by specifying them as compact intervals, taking into consideration the errors in modelling and measurement of transmission line parameters and also the continuous influence of load measurement errors and fluctuations in the load demand. The power flow equations are modelled as a set of nonlinear algebraic equations which are first linearised using Taylor series expansion and the solution is obtained by the Krawczyk's method of interval arithmetic. For the short circuit analysis the prefault conditions are obtained from power flow analysis and the faulty network is then solved using Thevenin's equivalent network as seen from the fault point. The proposed method is applied to 3 bus, 14 bus and 30 bus IEEE test systems where load currents and fault currents for each relay are obtained in bounded form and thus well-defined relay coordination pairs are available.
Keywords: interval mathematics; load flow analysis; uncertain data; Newton Raphson method; Intlab toolbox; Krawczyk's method; short circuit studies.
International Journal of Reliability and Safety, 2018 Vol.12 No.1/2, pp.166 - 186
Received: 03 Feb 2017
Accepted: 27 Feb 2018
Published online: 13 Jun 2018 *