Title: Digital relay software reliability allocation optimisation for transmission line protection

Authors: Diptendu Sihna Roy, A.K. Panda, Dusmanta Kumar Mohanta

Addresses: Department of Computer Science and Engineering, National Institute of Science and Technology, Berhampur, Orissa, India. ' Department of Computer Science and Engineering, National Institute of Science and Technology, Berhampur, Orissa, India. ' Department of Electrical and Electronics Engineering, Birla Institute of Technology, Ranchi, India

Abstract: Traditional methods for performance assessment of transmission line protective relays by hardware inspection and testing seem to be inadequate in case of contemporary digital relays. This is because about 80% of the engineering design content of digital relays is in the software area. Therefore, software reliability naturally emerges as an area of utmost interest. Recently, some digital relay algorithms have been proposed based on frequency domain using wavelet-neuro-fuzzy approaches for transmission line protection. In this paper, a software reliability allocation model is developed for the performance evaluation of such a digital relay for detection, classification and location of transmission line faults. Keeping the relative importance of different functions of a multi-functional digital relay, the software reliability allocation has been implemented using the analytical hierarchy process. The results contained in this paper validate the efficacy of the proposed method for optimising the utility of frequency domain-based digital relay for real-time implementation.

Keywords: digital relays; software reliability; AHP; analytical hierarchy process; DWT; discrete wavelet transforms; MRA; multi-resolution analysis; FIS; fuzzy inference systems; transmission line protection; protective relays; transmission line faults; transmission lines.

DOI: 10.1504/IJRS.2009.028585

International Journal of Reliability and Safety, 2009 Vol.3 No.4, pp.413 - 426

Available online: 19 Sep 2009 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article