Florina PIROI


29-58 METODĂ DE DETERMINARE RAPIDĂ A PUTERII UTILE LA O MAŞINĂ ASINCRONĂ

A RAPID METHOD FOR DETERMINING THE NET
POWER OF AN ASYNCHRONOUS MACHINE
This work presents a method to rapidly determine the net power of an
asynchronous machine running as a motor. For this we read a minimal set of
engine speed values, excitation winding current values, power factor values
when we know the nominal values of the tested engine. The find the net power
values we use the phases in drawing up the circle diagram for an electrical
machine. This method can easily used to find the electric energy balance of
various industrial units.
Keywords: net power, asynchronous motor, energy balance, circle
diagram
Cuvinte cheie: puterea utilă, motor asincron, bilanţ electroenergetic,
diagrama cercului

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29-45 STUDIUL STABILITĂŢII UNUI GRUP HIDRAULIC TURBINĂ-GENERATOR SINCRON AUTOEXCITAT LA UN M.H.C. AUTONOM

STABILITY STUDY FOR A TURBINE-SELF EXCITED
SYNCRONOUS GENERATOR HYDRAULIC GROUP OF A
AUTONOMOUS M.H.C.
This work aims to determine the stability of a self-excited synchronous
generator, which works in the autonomous mode, based on the link between
the hydraulic turbine–synchronous generator aggregate, the internal
aggregate’s generator angle, which depends on its load, and the opening angle
of the unit director. To verify the correctness of the relations presented in this
work the designed aggregate has been tested with sudden loads and various
resistive and inductive loads. The aggregate behaved as expected, remaining
stable following the transitory processes.
Keywords: static and dynamic stability, self-excited synchronous
generator, micro hydro power plant, self-adjustable drive
Cuvinte cheie: stabilitate statică şi dinamică, generator sincron
autoexcitat, microhidrocentrală, acţionare autoreglabilă

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