Bare shaft testing of rotating DC electrical machines using digital measurements and optimisation techniques

With the recent improvements in digital measurement techniques and modelling of electrical machines, researchers have focused on the possibility of commissioning, testing and condition monitoring AC electrical machines. Papers appeared in the literature from the mid 1980s. More recently, in the 1990s, interest has arisen for the bare-shaft testing of electrical machines. Most of the work reported has been in connection with induction machines. However, DC machines are a strong market contender, especially for low-voltage, mobile applications. In this paper, work is reported on DC machines, where a system for bare shaft testing has been developed. The theory used is explained and demonstrated by simulation. The paper concludes on the usefulness of the method and indicates areas for future work.