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Background: Variable Speed
Operation
In conventional pumped-storage power plants,
synchronous motor/generators are directly
connected to the grid and operate at a constant
speed.
Variable-speed operation of the hydro motor/
generators could increase the flexibility of hydro
power plants and enable optimal hydraulic
operation in both pumping and generating
modes. In this system, the rotational speed of
the motor/generator and pump/turbine does
not need to be constant and can be varied to
improve the hydraulic performance and reduce
the stresses. A variable-speed pumped-storage
power plant can also effectively contribute to the
grid stability.
There are two energy conversion
systems to realize the variable-
speed operation of the hydro
power plant: converter-fed
synchronous machine (CFSM)
and doubly-fed induction
machine (DFIM). The focusof this
research work is on the CFSM
with full-rated converter which
offers a higher degree of flexibility
and superior performance.
Background: Vibration Analysis
In the operation of the hydro generators, radial
magnetic forces are produced, causing vibration
in the stator.
The objective of this research work is to
investigate magnetic forces and vibration and
to identify the main factors affecting vibration
characteristics. The focus is on the fractional-
slot synchronous generators.
POST DOC.
Department of Electric
Power Engineering
2014-2017
Variable Speed
Operation of Hydro
Power Plants/ Vibration
Analysis of Hydro
Generators
Supervisor:
Arne Nysveen
Mostafa Valavi
CFSM installed at a pumped-storage power
plant in Switzerland by ABB
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