На основе численных расчетов вращающегося магнитного поля проведена оценка работы турбогенератора при несимметричной нагрузке. Анализируются временные функции магнитной индукции в неподвижных точках магнитной системы статора, форма и гармонический состав ЭДС его обмоток, их мощности. Результаты расчетов при несимметричной нагрузке сопоставляются с аналогичными результатами при симметричной нагрузке
На основі чисельних розрахунків обертового магнітного поля виконана оцінка роботи турбогенератора при несиметричному навантаженні. Аналізуються часові функції магнітної індукції в нерухомих точках магнітної системи статора, форма і гармонійний склад ЕРС його обмоток, їхні потужності. Результати розрахунків при несиметричному
навантаженні порівнюються з аналогічними результатами при симетричному навантаженні.
Purpose. Assessing the impact of load asymmetry of turbogenerator (TG) on the magnetic field distribution, on the electrical and
energy processes in it based on the numerical-field analysis within
the constraints regulated by the standards. Methodology. The
calculation model of TG has been constructed on the method of
symmetrical components of the three-phase current system. The
formed asymmetric system of the currents is used for multiposition numerical calculations of rotating magnetic fields. The
temporal functions of the electromagnetic quantities which are
subjected to the harmonic analysis are obtained on this basis.
Results. Test calculations are conducted on a three-phase 35 MW
TG during his work under autonomous unbalanced loading. The
analysis of the temporal functions of the magnetic induction at
different points of the TG stator and also similar functions of the
magnetic flux linkage, EMF phase stator windings and other variables have been executed. Originality. Problems of exploitation of
turbo-generators under unbalanced loading are detected by the
consideration of their electromagnetic system on the whole, but
not their simplified local parts, as usual. It has been shown that
the temporal functions of EMF of the phase stator windings under
unbalanced loading significantly differ in shape from sine waves
and from each other and contain a number of significant upper
harmonics. It has been detected that the phase currents would
contain not only the first but also significant upper harmonics
under unbalanced loading. Practical value. Analysis of the work
of TG under unbalanced loading showed the «top» level of problems of electromagnetic character. It has been established that the
function of the magnetic induction at the fixed points of the magnetic system on the whole have been changed but not in principle.
The temporal functions of EMF, and, hence, the voltage of the
stator phase windings significantly differ in shape from sine waves
and from each other, there is a considerable imbalance of active
powers generated by the individual phase windings of the stator.
The information provided will allow the measures to ensure a
durable and reliable operation of turbo-generators.
