Condition monitoring of substation equipment - A strategic maintenance planning
A lead time in advance, in terms of an alarm against impending failure of equipment, is a crucial issue in Thermal Power Plant, particularly for spare parts procurement and planning. Optimal utilization of operating machine necessitates an effective and strategic maintenance planning, not only for prolonged service life but to spot any adverse change in operating condition, as potential failure, sufficiently at an early stage. Estimation of subsequent degradation in machine condition on time scale is necessary to decide the time most suitable for actual maintenance. Selection of the parameters, which can tell the truth or provide the required information about the likely time of forced outage, is extremely important. It may be said that the selected parameters may be the choice of professional engineers, who practice in this state-of-art technology, but the goal remains invariably the same. A strategic planning, as such, forms an essential part of condition-based maintenance. In this context, it may be mentioned that the efforts made so far towards traditional fail-and-fix or reactive maintenance as well as for preventive maintenance have been receding from their usefulness, because they fail to provide any information as to when the machine condition deteriorated or the time when the required maintenance was exactly needed. Owing to a probably event of being caught unaware of the onset of problem and the maintenance for the same, the importance of condition monitoring, the challenges in execution of such a programme, and an impact on machine service suitability are a few issues, which have been addressed in the paper. The paper also highlights some typical case studies, where a timely action based on condition monitoring technique could avert a catastrophe of electrical equipment. The study is extended to condition-based maintenance planning regime by exemplifying the approach attempted for a few problematic areas so as to share experiences of the professionals and to advance the subject matter for wide adaptation.
Condition monitoring (CM), Dissolved Gas Analysis (DGA), Thermal Imaging (TI) Oil Analysis (OA), Furfural Analysis (FA), Gas Analysis (GA), Vacuum Leakage test (VLT), Switchgear Diagnostic System (SDS), Partiual discharge analysis (PDA or PD), Resistance measurement (RM), Tap Changer Diagnostic System (TDS).