Preparation of power transformer’s CBM implementation in PLN P3B Jawa Bali

Since year of 2004 PLN P3B Jawa Bali has decided to apply a new strategy of maintenance, i.e.: condition based maintenance (CBM) to its high voltage assets. Transformer, which is the most crucial and expensive asset in electrical power network, becomes the first priority to be applied on. Performing FMECA (failure mode effect and criticality analysis) in order to find failure path of each transformer subsystem and developing model became the first step should be done by PLN P3B Jawa Bali. There are two kinds of model developed by PLN P3B Jawa Bali; they are statistic model and physical model. This paper focuses on preparation of statistic model development. There are five kinds of data that PLN has been collected for 5 last years related to critical component found by FMECA process, they are : DGA (dissolved gas analysis), load and temperature (manual reading by operator), polarization Index, tan delta, oil characteristic test. Through data trending analysis, PLN has found that the data collected was not sufficient enough for model development. Therefore PLN has analyzed the problems and defined the new step to handle them, i.e.: Maintenance procedure standardization, DGA oil sampling standardization, Regular calibration of testing equipment.