Model development and validation of brushless exciters

This paper describes the process of performing site tests and model development of brushless exciters. Brushless exciters are often a source for model inaccuracy when studying synchronous machines and excitation system, which may lead to incorrect stabiliser design and poor performance. The process described here involves on site testing of the excitation system both with the generating unit operating open circuit and synchronised to the network which will enable the extraction of parameters to fit a model for the brushless exciter based on the IEEE Std 421.5. A case study is presented to discuss the approach.