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Measurement and Simulation of Hydro-Generator’s Asynchronous Operation

Z. Maljković ; University of Zagreb, Faculty of Electrical Engineering and Computing Croatia
Ž. Zebić ; University of Zagreb, Faculty of Electrical Engineering and Computing Croatia
M. Pavlica ; University of Zagreb, Faculty of Electrical Engineering and Computing Croatia

Sažetak

The extended testing of hydro-generator with Pelton turbine (rated 35 MVA) was performed
on a generator whose lifespan expired and it was going to be replaced. This was the perfect
opportunity to do some specific and uncommon testing. The complex testing plan was
designed in order to enable recording of as much relevant data as possible (electrical,
electromechanical, mechanical). Therefore, in some phases of testing, 29 to 44 quantities were
measured simultaneously. Among the tests, there are short circuits with lowered voltage, bad
synchronization at approximate angle of 15 degrees, asynchronous operation, generator overspeed
and operation with short circuited field winding on one pole.
The most interesting and the most critical operation during this testing is asynchronous
operation of hydro-generator [1, 2, 3, 4, 5], which is also very dangerous for generator and
drive equipment. During such operation synchronous generator operates at a speed unequal to
rated speed. This slip causes increased damping winding currents, which increases the thermal
stress of this winding beyond the designed level. This makes these tests very infrequent.
Asynchronous operating was achieved by decreasing the excitation current.
Complex mathematical model for computer simulation of hydro-generator’s asynchronous
operation has been made, taking into consideration the magnetic saturation, damper winding
and generator transformer’s influence. Results obtained by simulations have been compared
to those obtained by measurements.

Ključne riječi

Hydro-Generator; Asynchronous Operation; Testing; Simulation

Hrčak ID:

198383

URI

https://hrcak.srce.hr/198383

Datum izdavanja:

19.6.2017.

Posjeta: 646 *