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This paper presents an equipment for monitoring synchronous generators condition through characteristics of the time derivative of the external magnetic field. The developed monitoring methodology allows the identification of established or incipient faults, by detecting changes in the magnetic signature of the synchronous generator. In this methodology, the measurement of signals outside the machine gives this equipment a non-invasive characteristic, allowing its monitoring without interfering or disturbing its operation. The developed system includes the specification of magnetic field sensors, signal measurement and processing equipment, as well as software for analysis and monitoring. The validation of the methodology used in this system was carried out through the analysis of experimental data, presenting efficient results in the detection of electrical and mechanical faults in synchronous generators of an experimental test bench and a hydroelectric power plant. As a result, the commercial specification of this equipment was obtained and two units were implemented in a hydroelectric power plant to monitor 305 MVA synchronous generators.

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Solid rotor induction motors (SRIMs) are asynchronous motors suited for high speed applications. This work presents an experimental case study where standard loss segregation procedures for induction motors are performed with a two-phase smooth solid rotor induction motor in order to verify their applicability. Even though the machine is supposed to operate at high frequency, the tests are performed at reduced frequency and voltage in order to avoid the effects of time harmonics. An adjustment in the separation of losses is proposed to contemplate the effects of the high no-load slip, and the behavior of the stray losses under high per-unit slip is analyzed in a load test. The test results are finally extrapolated for the rated condition.

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