The paper describes a methodology to determine gas turbine operating state based on the analysis of normalized field data. This methodology consists in normalizing measured value with respect to that expected, calculated in the actual boundary conditions and working point. The normalization procedure, if applied on line, provides useful information to support the machine Health State determination.
In this paper, the methodology has been applied to field measurements taken on a 5 MW gas turbine running in a natural gas compression plant. The first results of field measurements analysis along a two year period are presented. Relations between compressor performance drops and the probable causes of malfunctioning have been identified. Some significant results are then presented.