Measurement of synchronous generator data from digital fault recorders for tracking of parameters and field degradation detection

This paper presents a description of advanced instrumentation technology developed at Arizona Public Service (APS) for on-line monitoring of large turbogenerators. These signals include three-phase generator voltages and currents, generator field winding voltages and currents, generator power angle and turbine front standard speed deviation. The data is collected by a 16 analog channel 10 bit digital fault recorder (DFR) for several operating conditions including steady state, transient events due to transmission line faults, etc., and staged tests. The paper also discusses the methodology behind the use of these measured signals for on-line tracking of the stability parameters of a synchronous generator. In this context, a procedure for the on-line estimation of machine parameters and turns ratios will be developed. Continuous monitoring of the machine parameters and turns ratios in real time may then be used for incipient failure detection.