Smart grid substation equipment maintenance management functionality based on control center SCADA data

Abstract

Classic approach to preventive maintenance of equipment in power system substations was based on periodical maintenance according to regulations and best practices recommended by vendors. SCADA system in HOPS is used primary for real-time monitoring and control of the equipment in substations. Real time data available in SCADA databases contain useful information for substation maintenance optimization based on operational conditions. Malfunctions and failures in the substations are monitored via SCADA system. Analyses of these data can be used to evaluate maintenance strategy and plan the reconstructions and replacement of the equipment. This article presents current maintenance management approach in HOPS, which is the only transmission system operator in Croatia, and possible improvements in efficiency of equipment maintenance using SCADA data. Prerequisite for the analyses of these kinds of data is standardization and unification of information names and structures. HOPS put a lot of effort in standardization of SCADA data during last refurbishment of control centers. Use of SCADA data for analysis drives the need for standardization and vice versa. Examples of statistical analyses of the SCADA data are done on multiple levels. High level analyses is used to provide the global overview of the real time data. It can point to suspicious information that require detailed analyses. The signals that appear often in the list can indicate that there is a problem in the primary equipment, monitoring system or alarm configuration. Low level analyses can be done on target information important for equipment maintenance. In this paper some low level analyses are presented for switching equipment, transformer lifetime, equipment in operation, and tap changer operation. An analysis is made for number of switching operations for breakers and disconnectors in different operational conditions. Preventive maintenance should be done based on number of switching in normal operations and even more often for breakers that are often interrupting fault current. SCADA data can be used for availability of the equipment and duration of failures thus providing valuable information to managers. An analysis on RTU communication availability is shown.