Abstract: | Two‐pole large generators are extensively used in power utilities. Growing demand for electric power in recent years has led to substantial increases in the capacity of generators. In line with this trend, our company has manufactured two‐pole turbine generators in the 900,000‐kVA to 1,200,000‐kVA classes. As the capacity of generators becomes larger, equivalent circuits are increasingly expected to improve their precision in estimating operation characteristics. The Park model has been widely used as an equivalent circuit model. The Park model with quadrature axis transient reactance $x_{q}^{prime}$ is claimed to be useful for accurately estimating the load rejection characteristics of turbine generators. However, it is difficult to measure $x_{q}^{prime}$, few studies based on measured data have appeared. As one of the few examples, we have conducted a measured data on a 500,000‐kVA‐class generator. Recently, the authors obtained test data on $x_{q}^{prime}$ of a 900,000‐kVA‐class generator. In this study, based on these data, we studied the effect of $x_{q}^{prime}$ using the finite element method and a transient analysis program (EMTP‐ATP). © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 177(3): 17–27, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21099 |