Employing instantaneous positive sequence symmetrical components for voltage sag source relative location

Modern industrial facilities are vulnerable to voltage sags and short interruptions as they were in the past to sustainable interruptions. Therefore, modern reliability assessment should include voltage sags and short interruptions. Hence, in order to improve power system reliability it is necessary to mitigate these voltage variations. One of the first steps towards this objective is to locate the source of these disturbances. This paper investigates a number of methods for sag source relative location. Said methods are based on different electrical parameters. Using instantaneous positive sequence components, five novel extended methods for voltage sag source location are proposed for accommodating the transient nature of voltage sag events and for improving unsuitable operation of methods on asymmetrical sags and earth faults. Due to the fact that short circuits are the main reason resulting in voltage sags, this paper focuses on the location of voltage sag sources due to line faults. A comparative analysis between the existing methods and the five novel extended methods is performed by applying extensive numerical simulations in a Brazilian regional transmission and sub-transmission utility. Finally, the effectiveness of all methods is obtained. The results show that the novel extended methods are more effective and among them, the extended methods based on reactive power can locate sag sources with an accuracy of 88%. Also, implementation of the novel extended methods on signal processors is easier with respect to the already implemented methods. (C) 2017 Elsevier B.V. All rights reserved.