Research into Power Distribution Network Condition Evaluation Method Based on Equipment Health Index

Abstract

To evaluate the health status of the power distribution network is of vital importance to condition-based maintenance of the power distribution network. By studying the power distribution network health condition using the theory of health index (HI), this paper proposes a method to evaluate the power distribution network health condition based on the equipment health index. To start with, the power distribution network health index model is built so as to ensure reliable and sustainable power supply for users. Meanwhile, the network equivalent method and the goal-oriented (GO) method in reliability analysis are employed to analyze and solve the model. Second, the existing equipment health index is used to work out the network health index, and examine the weak link of the power distribution network. Finally, the model is verified in the IEEE RBTS-Bus 2 Feeder Line 4 structure through simulation, and results suggest that this method is highly logical and convenient to realize computer programming, thus it can provide a viable plan for quantitative evaluation of the power distribution network health condition. Introduction Previously, indexes of reliability analysis were usually used to evaluate the power distribution network. Nevertheless, reliability analysis excessively relies on historical fault statistics of components. The lagging fault data and the basis provided by overall statistics of equipment of the same kind can hardly reflect performance attenuation within the valid service life of single equipment. Inspired by the health evaluation of the human body, the health diagnosis theory with power grid equipment’s real-time performance condition as the evaluation basis has been gradually introduced to the electric system, gradually demonstrating its advantages in electric maintenance and planning. In 2003, Hughes first developed the concept of “health index”, which represents the equipment’s real-time health condition by quantitatively evaluating the object’s health degree via the specific number [1]. Compared with the traditional reliability analysis, the theory of health diagnosis outperforms in accuracy and instantaneity. So far, the concept of electric system health diagnosis has been widely discussed. According to flow fingerprint characteristics, Literature [2] puts forward the preliminary diagnosis method for the power distribution system. In Literature [3], the electric transformer remaining service life evaluation method based on the health index heavily relies on the duration of operation, thus ignoring, to some extent, the practical operation condition. On the whole, researchers mostly concentrate on studying the health condition diagnosis of primary equipment with a higher voltage grade, but little research attention is paid to health diagnosis of the low-voltage equipment and network of the power distribution system. Because of the extensive existence and low cost of power distribution equipment, the equipment detection and evaluation, condition-based maintenance standards and decision-making methods adopted by the power transmission network might not be applicable to the power distribution network. Therefore, it has become an imperative to build the health diagnosis model specifically for the power distribution network, which makes full use of various equipment indexes to objectively reflect the power grid health condition and provide valid theoretical basis for formulation of power distribution 2nd International Conference on Electrical and Electronic Engineering (EEE 2019) Copyright © 2019, the Authors. Published by Atlantis Press. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). Advances in Engineering Research, volume 185