EXPERIMENTAL THERMOGRAPHY ANALYSIS AND REVERSE POLARITY OF COLLECTOR RINGS AND BRUSHES OF A STATIC EXCITATION SYSTEM ST1A

The use of carbon brushes is still a frequent practice in a number of machines, in this article emphasis is given to their application in static excitation systems for synchronous generation. In this context, an experimental analysis is presented for thermography and the reverse polarity of brushes and collector rings in a static excitation system. This model is denominated as ST1A in accordance with the standard IEEE Std. 421.1-2007. The experimental results were obtained for the excitation systems from 3 synchronous generators of 85,5 MVA, with field currents of the order of 1.154 kA. The data considered for analysis were collected from the temperature of each brush, from the collector ring above and below the rotor of the synchronous generator.