Offline testing for electrical machines has developed considerably over the last 30 years and this is represented in the summary tables above but also in the availability of a number of internationally recognised standards. But a review of the tables shows that the most developed off-line techniques are associated with the stator cores and windings and rotor windings of larger turbo-generators and hydro-generators. Not all offline tests are easy to perform and many cannot duplicate operational conditions. In many ways, the authors suggest that offline testing, particularly for larger machines, provides the background diagnostic information which should be used to direct the focus of subsequent online CM.

Chapter Contents:

• 12.1 Introduction
• 12.2 Stator core
• 12.2.1 General
• 12.2.2 Turbo-generators
• 12.2.3 Hydro-generators
• 12.3 Stator windings
• 12.3.1 Summary of offline tests
• 12.3.2 Frequency response analysis
• 12.4 Rotor windings
• 12.4.1 Summary of offline tests
• 12.4.2 Synchronous rotor surge tests
• 12.5 Conclusions

Inspec keywords: machine testing; condition monitoring; stators; rotors; hydroelectric generators; turbogenerators

Other keywords: electrical machines; stator cores; hydro-generators; background diagnostic information; offline monitoring; turbo-generators; rotor windings; offline testing

Subjects: Production facilities and engineering; a.c. machines